fix for bdb not ending up into libmysqld.a


bdb/dist/configure.ac:
  bdb bugfix: LTLIBOBJS didn't take --disable-shared into account
configure.in:
  build bdb with --disable-shared for libdb.a to go into libmysqld.a
libmysqld/examples/Makefile.am:
  incorrect "bugfix" undone. bdb should be in libmysqld.a