bg-card will be added to the class and password/username validation

bg-card should not be an id, ids should be unique in their use.

src/main/resources/templates/addUsers.html

@@ -12,7 +12,7 @@
         <br><br>
         <div class="container">
           <div class="row justify-content-center">
-            <div class="col-md-8" id="bg-card">
+            <div class="col-md-8 bg-card">
 
               <!-- User Settings Title -->
               <h2 class="text-center" th:text="#{adminUserSettings.header}">Admin User Control Settings</h2>