Don't make the App reload when users go to the dashboard

This is a alternative fix to @Milutin Kristofic change
(I434b5b0640d6786996ec971e7e00980cbb2595fc)

Change-Id: I0593187448154bfaf1806174e9971d2b12e6f526

polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js

@@ -309,11 +309,6 @@
       // so we'll just disable it altogether for now.
       delete linkObj.target;
 
-      // Because the user provided links may be arbitrary URLs, we don't know
-      // whether they correspond to any client routes. Mark all such links as
-      // external.
-      linkObj.external = true;
-
       return linkObj;
     },
 

polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.html

@@ -88,8 +88,8 @@ limitations under the License.
         {url: 'https://awesometown.com/#hashyhash'},
         {url: 'url', target: '_blank'},
       ].map(element._fixCustomMenuItem), [
-        {url: 'https://awesometown.com/#hashyhash', external: true},
-        {url: 'url', external: true},
+        {url: 'https://awesometown.com/#hashyhash'},
+        {url: 'url'},
       ]);
     });
 
@@ -176,7 +176,6 @@ limitations under the License.
         title: 'Plugins',
         links: [{
           name: 'Manage',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/index.html',
         }],
       }]);
@@ -207,7 +206,6 @@ limitations under the License.
         title: 'Projects',
         links: [{
           name: 'Project List',
-          external: true,
           url: '/plugins/myplugin/index.html',
         }],
       }]);
@@ -240,11 +238,9 @@ limitations under the License.
         title: 'Plugins',
         links: [{
           name: 'Manage',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/index.html',
         }, {
           name: 'Create',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/create.html',
         }],
       }]);
@@ -270,7 +266,6 @@ limitations under the License.
         title: 'Faves',
         links: defaultLinks[0].links.concat([{
           name: 'Manage',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/index.html',
         }]),
       }, {
@@ -296,7 +291,6 @@ limitations under the License.
         title: 'Your',
         links: userLinks.concat([{
           name: 'Manage',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/index.html',
         }]),
       }, {
@@ -322,7 +316,6 @@ limitations under the License.
         title: 'Browse',
         links: adminLinks.concat([{
           name: 'Manage',
-          external: true,
           url: 'https://gerrit/plugins/plugin-manager/static/index.html',
         }]),
       }]);