samr4: Use <SID=%s> in GetGroupsForUser

samr4: Use <SID=%s> in GetGroupsForUser

This way we avoid quoting problems in user's DNs

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Sep  1 23:49:14 CEST 2015 on sn-devel-104

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11488
(cherry picked from commit 841845dea35089a187fd1626c9752d708989ac7b)

Autobuild-User(v4-3-test): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(v4-3-test): Thu Sep  3 12:14:12 CEST 2015 on sn-devel-104