fix(module:modal): empty modal footer style

Author: xucr11

devui/modal/modal-footer.component.html

@@ -1,4 +1,4 @@
-<div class="modal-footer" [class.footer-empty]="!buttons?.length">
+<div *ngIf="buttons?.length" class="modal-footer">
   <d-button
     *ngFor="let button of buttons"
     [bsSize]="'md'"
@@ -9,6 +9,6 @@
     [width]="button.btnwidth"
     [autofocus]="button.autofocus"
     [disabled]="button.disabled"
-  >{{ button.text }}
+    >{{ button.text }}
   </d-button>
 </div>

devui/modal/modal-footer.component.scss

@@ -1,7 +1,3 @@
 .modal-footer {
   padding-bottom: 24px;
-
-  &.footer-empty {
-    padding: 0;
-  }
 }