Invert logic on "New" dropdown tests

Feature flags are enabled by default in tests, so some test were not
testing something meaningful.

ee/spec/views/layouts/header/_new_dropdown.haml_spec.rb

@@ -28,25 +28,29 @@ describe 'layouts/header/_new_dropdown' do
         group.add_owner(user)
       end
 
-      it 'does not have "New epic" link' do
+      context 'with the epics license' do
+        before do
+          stub_licensed_features(epics: true)
+        end
+
+        it 'has a "New epic" link' do
           render
 
-        expect(rendered).not_to have_link(
+          expect(rendered).to have_link(
             'New epic',
             href: new_group_epic_path(group)
           )
         end
 
-      context 'when epics are enabled' do
+        context 'with the create_epic_form feature flag disabled' do
           before do
-          stub_licensed_features(epics: true)
-          stub_feature_flags(create_epic_form: true)
+            stub_feature_flags(create_epic_form: false)
           end
 
-        it 'has a "New epic" link' do
+          it 'does not have "New epic" link' do
             render
 
-          expect(rendered).to have_link(
+            expect(rendered).not_to have_link(
               'New epic',
               href: new_group_epic_path(group)
             )
@@ -54,4 +58,5 @@ describe 'layouts/header/_new_dropdown' do
         end
       end
     end
+  end
 end