fixed dashboard projects nav item being active

it is now only shown as active when on the dashbord/projects controller

[ci skip]

app/assets/stylesheets/new_nav.scss

@@ -131,11 +131,14 @@ header.navbar-gitlab-new {
     background-color: $gl-gray-light;
   }
 
-  .search-input,
-  .search-input::placeholder {
+  .search-input {
     color: $gray-normal;
   }
 
+  .search-input::placeholder {
+    color: $gray-dark;
+  }
+
   .location-badge {
     color: $gray-normal;
     background-color: #2d2d2d;

app/views/layouts/nav/_new_dashboard.html.haml

 %ul.list-unstyled.navbar-sub-nav
-  = nav_link(path: ['root#index', 'projects#trending', 'projects#starred', 'dashboard/projects#index'], html_options: {class: "#{project_tab_class} home"}) do
+  = nav_link(path: ['root#index', 'projects#trending', 'projects#starred', 'dashboard/projects#index'], html_options: {class: "home"}) do
     = link_to dashboard_projects_path, title: 'Projects', class: 'dashboard-shortcuts-projects' do
       Projects