Fix prerender task

Author: devversion

src/lib/slide-toggle/slide-toggle.html

@@ -1,7 +1,7 @@
 <label class="mat-slide-toggle-label" #label>
 
   <div class="mat-slide-toggle-bar"
-       [class.mat-slide-toggle-bar-no-side-margin]="!labelContent.textContent.trim()">
+       [class.mat-slide-toggle-bar-no-side-margin]="!checkboxLabel.textContent || !labelContent.textContent.trim()">
 
     <input #input class="mat-slide-toggle-input cdk-visually-hidden" type="checkbox"
            [id]="inputId"