Connect signal for VisualScript "Yield Signal" using oneshot mode

Since the first call to a VisualScriptFunctionState invalidates the
state, any further call results in errors.

modules/visual_script/visual_script.cpp

@@ -2289,7 +2289,7 @@ void VisualScriptFunctionState::connect_to_signal(Object *p_obj, const String &p
 		binds.push_back(p_binds[i]);
 	}
 	binds.push_back(Ref<VisualScriptFunctionState>(this)); //add myself on the back to avoid dying from unreferencing
-	p_obj->connect(p_signal, this, "_signal_callback", binds);
+	p_obj->connect(p_signal, this, "_signal_callback", binds, CONNECT_ONESHOT);
 }
 
 bool VisualScriptFunctionState::is_valid() const {