Revert "Fix issue with tray icon double clicking."

This reverts commit a120c8eb28c0dfcdfdb0981c63147bb37d45df2c.

Turns out this prevented Mumble from being able to raise
itself in front of a maximized application. The click
not being reported after using the activateWindow function
is probably a Qt bug and if it's reproducible in a small
sample should be reported.