[464437] Broker: Fix bridge prefixes operation.

Fix bridge prefixes only working for the first outgoing message.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=464437

ChangeLog.txt

@@ -1,11 +1,16 @@
 1.4.2 - 201504xx
 ================
 
+Broker:
+- Fix bridge prefixes only working for the first outgoing message. Closes
+  #464437.
+
 Client library:
 - Inflight message count wasn't being decreased for outgoing messages using
   QoS 2, meaning that only up to 20 QoS 2 messages could be sent. This has
   been fixed. Closes #464436.
 
+
 1.4.1 - 20150403
 ================
 

lib/send_mosq.c

@@ -149,7 +149,7 @@ int _mosquitto_send_publish(struct mosquitto *mosq, uint16_t mid, const char *to
 							return MOSQ_ERR_NOMEM;
 						}
 						snprintf(topic_temp, len, "%s%s", cur_topic->remote_prefix, mapped_topic);
-						cur_topic->remote_prefix[len] = '\0';
+						topic_temp[len] = '\0';
 						_mosquitto_free(mapped_topic);
 						mapped_topic = topic_temp;
 					}