修复窗口在较小模式下最小化/关闭按钮不居中的问题

src/renderer/components/core/Aside.vue

@@ -147,7 +147,7 @@ export default {
     height: @control-btn-width;
     background: none;
     border: none;
-    // display: flex;
+    display: flex;
     // justify-content: center;
     // align-items: center;
     outline: none;

src/renderer/components/core/Toolbar.vue

@@ -183,6 +183,7 @@ export default {
   }
 
   button {
+    display: flex;
     position: relative;
     width: @control-btn-width;
     height: @control-btn-width;