Mongosql imports made celery get set up before we wanted it via ./bin/gmg commands

Just moved the import into the actual function.  That resolved the issue!

mediagoblin/gmg_commands/mongosql.py

@@ -14,12 +14,11 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from mediagoblin.db.sql.convert import run_conversion
-
 
 def mongosql_parser_setup(subparser):
     pass
 
 
 def mongosql(args):
+    from mediagoblin.db.sql.convert import run_conversion
     run_conversion(args.conf_file)