Avoid potentially existing id, and fix 404 test

ee/spec/controllers/groups/epic_issues_controller_spec.rb

@@ -132,7 +132,7 @@ describe Groups::EpicIssuesController do
       end
 
       context 'when user does not have permissions to delete the link' do
-        it 'returns status 404' do
+        it 'returns status 403' do
           subject
 
           expect(response.status).to eq(403)
@@ -167,9 +167,11 @@ describe Groups::EpicIssuesController do
 
       context 'when the epic_issue record does not exists' do
         it 'returns status 404' do
-          delete :destroy, params: { group_id: group, epic_id: epic.to_param, id: 9999 }
+          group.add_developer(user)
 
-          expect(response.status).to eq(403)
+          delete :destroy, params: { group_id: group, epic_id: epic.to_param, id: 0 }
+
+          expect(response.status).to eq(404)
         end
       end
     end