fix(ConnectionLine):修复AB两点重复连接，有多条连接线，触发重启的BUG

Assets/Script/Gameplay/Connect/ConnectionLineManager.cs

@@ -26,6 +26,16 @@ namespace Script.Gameplay.Connect
 
         public ConnectionLine GenerateConnectionLine(IConnectable a, IConnectable b)
         {
+            // 先检测 a b 点是否已经存在连接线
+            foreach (var aline in a.ConnectionLines)
+            {
+                if (aline.PointA.GetGameObject() == b.GetGameObject() || aline.PointB.GetGameObject() == b.GetGameObject())
+                {
+                    Debug.Log("ab点间已经存在连接线");
+                    return null;
+                }
+            }
+            
             GameObject lineObject = Instantiate(linePrefab, this.transform);
             ConnectionLine connectionLine = lineObject.GetComponent<ConnectionLine>();
             if (connectionLine != null)