Ensure that runners registration token is present

app/views/ci/admin/runners/index.html.haml

@@ -3,7 +3,7 @@
     To register a new runner you should enter the following registration token.
     With this token the runner will request a unique runner token and use that for future communication.
     Registration token is
-    %code{ id: 'runners-token' } #{current_application_settings.runners_registration_token}
+    %code{ id: 'runners-token' } #{current_application_settings.ensure_runners_registration_token}
 
 .bs-callout.clearfix
   .pull-left

lib/ci/api/helpers.rb

@@ -23,7 +23,7 @@ module Ci
       end
 
       def runner_registration_token_valid?
-        params[:token] == current_application_settings.runners_registration_token
+        params[:token] == current_application_settings.ensure_runners_registration_token
       end
 
       def update_runner_last_contact

spec/features/ci/admin/runners_spec.rb

@@ -63,7 +63,7 @@ describe "Admin Runners" do
   end
 
   describe 'runners registration token' do
-    let!(:token) { current_application_settings.runners_registration_token }
+    let!(:token) { current_application_settings.ensure_runners_registration_token }
     before { visit ci_admin_runners_path }
 
     it 'has a registration token' do