Fix the generated markup of NULL by inserting a space

include/ua_server.h

@@ -1232,7 +1232,7 @@ UA_Server_deleteReference(UA_Server *server, const UA_NodeId sourceNodeId,
  * The method ``UA_Server_triggerEvent`` "triggers" an event by adding it to all monitored items of the specified
  * origin node and those of all its parents. Any filters specified by the monitored items are automatically applied.
  * Using this method deletes the node generated by ``UA_Server_createEvent``. The `EventId` for the new event is
- * generated automatically and is returned through ``outEventId``.``NULL`` can be passed if the `EventId` is not
+ * generated automatically and is returned through ``outEventId``. ``NULL`` can be passed if the `EventId` is not
  * needed. ``deleteEventNode`` specifies whether the node representation of the event should be deleted after invoking
  * the method. This can be useful if events with the similar attributes are triggered frequently. ``UA_TRUE`` would
  * cause the node to be deleted. */