Global: fix migrateDataDir() not migrating the data directory
Global: fix migrateDataDir() not migrating the data directory

rename() was failing because it doesn't expect the new directory to exist.

From Qt's documentation (http://doc.qt.io/qt-5/qdir.html#rename):
"On most file systems, rename() fails only if oldName does not exist, or if a file with the new name already exists."

Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble,Lartza/mumble