ensure all queue members are initialized to not produce errors on calling...

ensure all queue members are initialized to not produce errors on calling remove function, without insert them on a queue

src/ngx_http_push_stream_module_ipc.c

@@ -465,7 +465,7 @@ ngx_http_push_stream_broadcast(ngx_http_push_stream_channel_t *channel, ngx_http
         }
     }
 
-    if ((msg->queue.prev == NULL) && (msg->queue.next == NULL)) {
+    if (ngx_queue_empty(&msg->queue)) {
         ngx_shmtx_lock(&shpool->mutex);
         ngx_http_push_stream_mark_message_to_delete_locked(msg, mcf->shm_data);
         ngx_shmtx_unlock(&shpool->mutex);

src/ngx_http_push_stream_module_subscriber.c

@@ -417,6 +417,7 @@ ngx_http_push_stream_subscriber_prepare_request_to_keep_connected(ngx_http_reque
         return NULL;
     }
 
+    ngx_queue_init(&worker_subscriber->worker_queue);
     worker_subscriber->longpolling = 0;
     worker_subscriber->request = r;
     worker_subscriber->worker_subscribed_pid = ngx_pid;
@@ -629,6 +630,8 @@ ngx_http_push_stream_create_channel_subscription(ngx_http_request_t *r, ngx_http
 
     subscription->channel = channel;
     subscription->subscriber = subscriber;
+    ngx_queue_init(&subscription->queue);
+    ngx_queue_init(&subscription->channel_worker_queue);
 
     return subscription;
 }

src/ngx_http_push_stream_module_utils.c

@@ -251,13 +251,12 @@ ngx_http_push_stream_convert_char_to_msg_on_shared_locked(ngx_http_push_stream_m
     msg->formatted_messages = NULL;
     msg->deleted = 0;
     msg->expires = 0;
-    msg->queue.prev = NULL;
-    msg->queue.next = NULL;
     msg->id = id;
     msg->workers_ref_count = 0;
     msg->time = (id < 0) ? 0 : ngx_time();
     msg->tag = (id < 0) ? 0 : ((msg->time == shm_data->last_message_time) ? (shm_data->last_message_tag + 1) : 1);
     msg->qtd_templates = mcf->qtd_templates;
+    ngx_queue_init(&msg->queue);
 
     if ((msg->raw.data = ngx_slab_alloc_locked(shpool, len + 1)) == NULL) {
         ngx_http_push_stream_free_message_memory_locked(shpool, msg);