Add form for runner config to run untagged jobs

app/views/projects/runners/_form.html.haml

@@ -5,6 +5,12 @@
       .checkbox
         = f.check_box :active
         %span.light Paused runners don't accept new builds
+  .form-group
+    = label :run_untagged, 'Run untagged jobs', class: 'control-label'
+    .col-sm-10
+      .checkbox
+        = f.check_box :run_untagged
+        %span.light This runner can pick jobs without tags
   .form-group
     = label_tag :token, class: 'control-label' do
       Token