build: fix build with gpfs support - add missing dependency to samba-debug

build: fix build with gpfs support - add missing dependency to samba-debug

Fix for bug #11421 part 2.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=11421

Pair-programmed-with: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Björn Baumbach <bb@sernet.de>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
Reviewed-by: Martin Schwenke <martin@meltin.net>
Autobuild-User(master): Martin Schwenke <martins@samba.org>
Autobuild-Date(master): Wed Jul 29 13:38:59 CEST 2015 on sn-devel-104

(cherry picked from commit d57e4ac3de5f53346a8d7c3f96825c1345b58f6a)