Fix specs

Spinach was right, I was a fool..

app/models/issue.rb

@@ -98,6 +98,7 @@ class Issue < ActiveRecord::Base
   end
 
   def related_branches
+    return [] if self.project.empty_repo?
     self.project.repository.branch_names.select do |branch|
       branch =~ /\A#{iid}-(?!\d+-stable)/i
     end

spec/features/issues/new_branch_button_spec.rb

@@ -24,7 +24,7 @@ feature 'Start new branch from an issue', feature: true do
       end
       let(:referenced_mr) do
         create(:merge_request, :simple, source_project: project, target_project: project,
-                                description: "Fixes ##{issue.iid}")
+                                        description: "Fixes ##{issue.iid}")
       end
 
       before do