[ml-service] Change caps prop to caps filter of appsrc

The ml-service-query-client test sometimes fails.
Let's revert the change and repeat the tests.

Related issue: #421

Signed-off-by: gichan2-jang <gichan2.jang@samsung.com>

c/src/ml-api-service-query-client.c

@@ -176,7 +176,7 @@ ml_service_query_create (ml_option_h option, ml_service_h * handle)
   prop = g_string_free (tensor_query_client_prop, FALSE);
   description =
       g_strdup_printf
-      ("appsrc name=srcx caps=%s ! tensor_query_client %s name=qcx ! tensor_sink name=sinkx async=false sync=false",
+      ("appsrc name=srcx ! %s ! tensor_query_client %s name=qcx ! tensor_sink name=sinkx async=false sync=false",
       caps, prop);
 
   status = ml_pipeline_construct (description, NULL, NULL, &pipe_h);