DOI link does not open the browser

[Mailaender]

On KDE/Firefox the weblink buttons added in https://github.com/eclipse/chemclipse/issues/1597 do not work.

java.lang.UnsupportedOperationException: The BROWSE action is not supported on the current platform!
	at java.desktop/java.awt.Desktop.checkActionSupport(Desktop.java:381)
	at java.desktop/java.awt.Desktop.browse(Desktop.java:531)
	at org.eclipse.chemclipse.support.editor.SystemEditor.browse(SystemEditor.java:50)
	at org.eclipse.chemclipse.ux.extension.xxd.ui.methods.SettingsPreferencesPage$3.widgetSelected(SettingsPreferencesPage.java:234)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:252)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5855)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1529)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:5065)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4517)
	at org.eclipse.jface.window.Window.runEventLoop(Window.java:823)
	at org.eclipse.jface.window.Window.open(Window.java:799)
	at org.eclipse.chemclipse.ux.extension.xxd.ui.methods.SettingsWizard.openEditPreferencesWizard(SettingsWizard.java:69)
	at org.eclipse.chemclipse.ux.extension.xxd.ui.methods.SettingsWizard.getSettings(SettingsWizard.java:139)
	at org.eclipse.chemclipse.ux.extension.xxd.ui.swt.editors.ExtendedChromatogramUI.executeSupplier(ExtendedChromatogramUI.java:720)
	at org.eclipse.chemclipse.ux.extension.xxd.ui.swt.editors.ProcessorSupplierMenuEntry.execute(ProcessorSupplierMenuEntry.java:96)
	at org.eclipse.swtchart.extensions.core.ScrollableChart$8.widgetSelected(ScrollableChart.java:1814)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:252)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5855)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1529)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:5065)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4517)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:152)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:639)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:546)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.chemclipse.rcp.app.ui.internal.support.ApplicationSupportDefault.start(ApplicationSupportDefault.java:25)
	at org.eclipse.chemclipse.rcp.app.ui.Application.start(Application.java:27)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:208)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:143)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:109)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:439)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:271)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:651)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:588)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1459)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1432)