* fix a memory corruption due to sligtly different semantics of btree iterators:

* fix a memory corruption due to sligtly different semantics of btree iterators:

       // We use the key() method here, and not something like it->first
       // because the btree only returns (iterator-) temporary value pairs.
       // If we returned the first component of those here, we get an
       // invalid reference and therefore strange crashes.
       return it.key();

* This should fix the completion for Windows users hopefully.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@23321 a592a061-630c-0410-9148-cb99ea01b6c8