Removed .col-form-label from vertical form example (#24771)

Fixes #24739

Author: Daniel Niccoli

docs/4.0/components/forms.md

@@ -264,11 +264,11 @@ The `.form-group` class is the easiest way to add some structure to forms. Its o
 {% example html %}
 <form>
   <div class="form-group">
-    <label class="col-form-label" for="formGroupExampleInput">Example label</label>
+    <label for="formGroupExampleInput">Example label</label>
     <input type="text" class="form-control" id="formGroupExampleInput" placeholder="Example input">
   </div>
   <div class="form-group">
-    <label class="col-form-label" for="formGroupExampleInput2">Another label</label>
+    <label for="formGroupExampleInput2">Another label</label>
     <input type="text" class="form-control" id="formGroupExampleInput2" placeholder="Another input">
   </div>
 </form>