multiqueue: fix warning: ‘is_query’ may be used uninitialized in this function
Fixes:
../plugins/elements/gstmultiqueue.c: In function ‘gst_multi_queue_loop’:
../plugins/elements/gstmultiqueue.c:2394:19: warning: ‘is_query’ may be used uninitialized in this function [-Wmaybe-uninitialized]
2394 | if (object && !is_query)
| ^~~~~~~~~