Fix middle mouse drag.

src/litegraph.js

@@ -6257,11 +6257,13 @@ LGraphNode.prototype.executeAction = function(action)
 																					,posAdd:[!mClikSlot_isOut?-30:30, -alphaPosY*130] //-alphaPosY*30]
 																					,posSizeFix:[!mClikSlot_isOut?-1:0, 0] //-alphaPosY*2*/
 																				});
-								
+							skip_action = true;
 						}
 					}
 				}
-			} else if (!skip_action && this.allow_dragcanvas) {
+			}
+
+			if (!skip_action && this.allow_dragcanvas) {
             	//console.log("pointerevents: dragging_canvas start from middle button");
             	this.dragging_canvas = true;
             }