Remember OSD/popup location

[ThomasSeeker]

As of issue #16 this should have been resolved, but at least for outgoing calls (which I did test) the position of the in-call OSD is not being remembered here with version v1.10.2..

Sorry, if opening this again this way is the wrong route, but I could not reopen the original issue.

EDIT: After each restart it is placed at the top right corner of the screen again.