Fix logging messages in hub/server/src/main/java/alluxio/hub/manager/process/ManagerProcessContext.java

[apc999]

https://github.com/Alluxio/alluxio/blob/60102fdc4fbce87b236ddecf483284945fbfd5e0/hub/server/src/main/java/alluxio/hub/manager/process/ManagerProcessContext.java#L393

There are a few wrong references to error in logging, like LOG.error("Error connecting to hosted hub {}", e); should be LOG.error("Error connecting to hosted hub: ", e);, See more instructions https://docs.alluxio.io/os/user/stable/en/contributor/Code-Conventions.html#error-log-level

[witheredwood]

/assign @witheredwood