GUAC-1176: Handle insufficient credentials distinctly from invalid credentials.

guacamole/src/main/webapp/index.html

@@ -50,7 +50,8 @@
         </div>
 
         <!-- Login screen for logged-out users -->
-        <guac-login ng-show="expectedCredentials" form="expectedCredentials"></guac-login>
+        <guac-login ng-show="expectedCredentials" form="expectedCredentials"
+                    values="acceptedCredentials"></guac-login>
         
         <script type="text/javascript" src="app.js"></script>
     </body>