fixed @compare_result null done

app/views/compare/show.json.jbuilder

@@ -1,6 +1,7 @@
 json.commits_count @compare_result['CommitsCount']
 # json.commits @compare_result['Commits'], partial: 'pull_requests/commit', as: :commit
 json.commits do
+  if @compare_result['Commits'].present?
     json.array! @compare_result['Commits'][@page_offset...(@page_offset + @page_limit)] do |commit|
       json.author do
         json.partial! 'repositories/commit_author', locals: { user: render_cache_commit_author(commit['Committer']), name: commit['Committer']['Name'] }
@@ -15,6 +16,7 @@ json.commits do
       json.message commit['CommitMessage']
       json.sha commit['Sha']
     end
+  end
 end
 
 json.diff do