Address Philip's review comments

app/modules/node.c

@@ -453,7 +453,6 @@ static int node_compile( lua_State* L )
 static task_handle_t do_node_task_handle;
 static void do_node_task (task_param_t task_fn_ref, uint8_t prio)
 {
-  UNUSED(prio);
   lua_State* L = lua_getstate();
   lua_rawgeti(L, LUA_REGISTRYINDEX, (int)task_fn_ref);
   luaL_unref(L, LUA_REGISTRYINDEX, (int)task_fn_ref);

docs/en/modules/node.md

@@ -433,7 +433,7 @@ If the priority is omitted then  this defaults  to `node.task.MEDIUM_PRIORITY`
 ```lua
 for i = node.task.LOW_PRIORITY, node.task.HIGH_PRIORITY do 
   node.task.post(i,function(p2)
-    print("priority is ..p2)
+    print("priority is "..p2)
   end) 
 end      
 ```