Add usage assertions when deleting a queue (#1449)

Adds an assertion which helps to verify
a queue is not in use before deletion.

queue.c

diff --git a/queue.c b/queue.c
index 37d953a..83c7ac7 100644
--- a/queue.c
+++ b/queue.c
@@ -2261,6 +2261,8 @@
     traceENTER_vQueueDelete( xQueue );
 
     configASSERT( pxQueue );
+    configASSERT( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) );
+    configASSERT( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) );
     traceQUEUE_DELETE( pxQueue );
 
     #if ( configQUEUE_REGISTRY_SIZE > 0 )