Don't even attempt to unload libqstart_gtklo.so again

...for no apparent gain.  IdleUnloader introduced in
a8b42ddd66bba4b6f26a4d2d793051752989938e "Fix i#101245#" was probably a
misguided reaction to osl::Module's dtor starting to call dlclose back then.

Change-Id: I9a5e99d8cfba13e3750331597d64f58135537e9b