Fixed self-service UI.

The Identity tab for self-service UI was missing a label and there
was a bug in navigation.js that was exposed because of that.

install/ui/navigation.js

@@ -145,10 +145,10 @@ IPA.navigation = function(spec) {
                     continue;
                 }
                 tab.entity = entity;
-            }
 
-            if (!tab.label) {
-                tab.label = entity.label;
+                if (!tab.label) {
+                    tab.label = entity.label;
+                }
             }
 
             $('<li/>').append($('<a/>', {

install/ui/webui.js

@@ -77,7 +77,7 @@ IPA.self_serv_navigation = function(spec) {
     spec = spec || {};
 
     spec.tabs = [
-        {name: 'identity', children: [
+        {name: 'identity', label: IPA.messages.tabs.identity, children: [
             {entity: 'user'},
             {entity: 'group'}
         ]}];