iotests/148: use skip_if_unsupported

Skip test-case with quorum if quorum is not whitelisted.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200430124713.3067-4-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/148

@@ -47,6 +47,7 @@ sector = "%d"
 ''' % bad_sector)
         file.close()
 
+    @iotests.skip_if_unsupported(['quorum'])
     def setUp(self):
         driveopts = ['driver=quorum', 'vote-threshold=2']
         driveopts.append('read-pattern=%s' % self.read_pattern)