Crats should not add users to import on frwiktionary

This patch removes the ability to add users to, and
remove from, the 'import' group from bureaucrats on
the French Wiktionary.

This ability was granted to bureaucrats in bug 23545,
apparently by mistake.

Removal requested by steward Quentinv57; see bug for
more information.

Bug: 61829
Change-Id: Ic17196c5699c5200ea2a6bdbf0470d41a63b9306