It appears that since cd0046bc,
2 tinderboxes fail on including the generated sqlbison.hxx;
it turns out one of the inclusions of that in svx is unnecessary and the
other is used to call a virtual function, which can apparently be done
without linking; just link svx to dbtools anyway, that should fix the
build.

Change-Id: I7f7b1c4e9561c4dd2b820b173d05bdd5d4c6ba6d