Dialog: only destroy slot when destroyOnClose is true

packages/dialog/src/component.vue

@@ -9,7 +9,6 @@
       @click.self="handleWrapperClick">
       <div
         role="dialog"
-        :key="key"
         aria-modal="true"
         :aria-label="title || 'dialog'"
         :class="['el-dialog', { 'is-fullscreen': fullscreen, 'el-dialog--center': center }, customClass]"
@@ -112,8 +111,7 @@
 
     data() {
       return {
-        closed: false,
-        key: 0
+        closed: false
       };
     },
 
@@ -133,9 +131,7 @@
           this.$el.removeEventListener('scroll', this.updatePopper);
           if (!this.closed) this.$emit('close');
           if (this.destroyOnClose) {
-            this.$nextTick(() => {
-              this.key++;
-            });
+            this.rendered = false;
           }
         }
       }