Update loginuserpass.twig, sharpen admin auth hack

mymodule/themes/fancytheme/core/loginuserpass.twig

@@ -16,7 +16,7 @@
             <form method="post">
                 <h2 class="sr-only">Login Form</h2>
                 <div class="illustration"><img src="/img/M4_LAB_LOGO.png" width="130"></div>
-		{%- if 'admin' in attribute(queryParams, "AuthState") -%}
+		{%- if 'AuthId=admin' in attribute(queryParams, "AuthState") -%}
 	                <div class="form-group"><input id="username" class="form-control" type="text" name="username" placeholder="Administrator"></div>
                 {%- else -%}
 	                <div class="form-group"><input id="username" class="form-control" type="email" name="username" placeholder="E-Mail-Adresse"></div>