Fixed bug in mentat-backup script.

Wrong string literal used when generating backup shell command.

bin/mentat-backup.py

@@ -197,12 +197,12 @@ class MentatBackupScript(pyzenkit.zenscript.ZenScript):
             (coll, ts_attr, system) = rule
             if system:
                 self.logger.info("Performing backup of system collection '{}'".format(coll))
-                cmd = r"mongodump -o {} -d '{}' -c '{}'".format(dir_tmp, 'mentat', coll)
+                cmd = "mongodump -o {} -d '{}' -c '{}'".format(dir_tmp, 'mentat', coll)
                 result['dumpcommands'].append(cmd)
                 self.execute_command(cmd)
             else:
                 self.logger.info("Performing backup of collection '{}'".format(coll))
-                cmd = r"mongodump -o {} -d '{}' -c '{}' -q '{{\"{}\": {{\"\$gte\": {}, \"\$lt\": {}}}}}'".format(dir_tmp, 'mentat', coll, ts_attr, time_l, time_h)
+                cmd = "mongodump -o {} -d '{}' -c '{}' -q '{{\"{}\": {{\"$gte\": {}, \"$lt\": {}}}}}'".format(dir_tmp, 'mentat', coll, ts_attr, time_l, time_h)
                 result['dumpcommands'].append(cmd)
                 self.execute_command(cmd)