Fix MQTT v5 sub opts being set for v3 subs.

Closes #1353. Thanks to Ben Barbour.

ChangeLog.txt

@@ -7,6 +7,10 @@ Broker:
 - Windows: Allow other applications access to the log file when running.
  Closes #515.
 
+Client library:
+- Fix MQTT v5 subscription options being incorrectly set for MQTT v3
+ subscriptions. Closes #1353.
+
 
 1.6.3 - 20190618
 ================

lib/actions.c

@@ -200,6 +200,9 @@ int mosquitto_subscribe_multiple(struct mosquitto *mosq, int *mid, int sub_count
  return MOSQ_ERR_OVERSIZE_PACKET;
  }
  }
+ if(mosq->protocol == mosq_p_mqtt311 || mosq->protocol == mosq_p_mqtt31){
+ options = 0;
+ }
 
  return send__subscribe(mosq, mid, sub_count, sub, qos|options, outgoing_properties);
 }

lib/mosquitto.h

@@ -921,8 +921,9 @@ libmosq_EXPORT int mosquitto_subscribe_v5(struct mosquitto *mosq, int *mid, cons
  * familiar with this, just think of it as a safer "char **",
  * equivalent to "const char *" for a simple string pointer.
  * qos - the requested Quality of Service for each subscription.
- * options - options to apply to this subscription, OR'd together. Set to 0 to
- * use the default options, otherwise choose from the list:
+ * options - options to apply to this subscription, OR'd together. This
+ * argument is not used for MQTT v3 susbcriptions. Set to 0 to use
+ * the default options, otherwise choose from the list:
  * MQTT_SUB_OPT_NO_LOCAL - with this option set, if this client
  * publishes to a topic to which it is subscribed, the
  * broker will not publish the message back to the