Fix：修复批量执行类添加同名任务时任务未更新为最小任务的问题

simple-mind-map/src/utils/BatchExecution.js

@@ -12,6 +12,7 @@ class BatchExecution {
   //  添加任务
   push(name, fn) {
     if (this.has[name]) {
+      this.replaceTask(name, fn)
       return
     }
     this.has[name] = true
@@ -22,6 +23,19 @@ class BatchExecution {
     this.nextTick()
   }
 
+  // 替换任务
+  replaceTask(name, fn) {
+    const index = this.queue.findIndex(item => {
+      return item.name === name
+    })
+    if (index !== -1) {
+      this.queue[index] = {
+        name,
+        fn
+      }
+    }
+  }
+
   //   执行队列
   flush() {
     let fns = this.queue.slice(0)