Merge branch '6664-extract-discussion-specs' into 'master'

Remove extra line in `spec/models/merge_request_spec.rb`

Closes #6664

See merge request gitlab-org/gitlab-ee!10589

spec/models/merge_request_spec.rb

@@ -476,7 +476,6 @@ describe MergeRequest do
       it 'does not cache issues from external trackers' do
         issue  = ExternalIssue.new('JIRA-123', subject.project)
         commit = double('commit1', safe_message: "Fixes #{issue.to_reference}")
-
         allow(subject).to receive(:commits).and_return([commit])
 
         expect { subject.cache_merge_request_closes_issues!(subject.author) }.not_to raise_error