Don't select an access level if already selected.

1. This is in regard to the protected branches feature spec.

2. For example, if "Masters" is already selected, don't re-select
   "Masters" during the spec.

3. This is due to a bug in the frontend implementation, where selecting
   an already-selected access level _deselects_ it, which is something
   we don't need. I'll create a separate issue for this.

4. This hasn't turned up before, because we were manually creating
   missing access levels prior to e805a647. Now, we just use nested
   attributes, and missing access levels fail validation.

spec/features/protected_branches_spec.rb

@@ -93,9 +93,13 @@ feature 'Projected Branches', feature: true, js: true do
         visit namespace_project_protected_branches_path(project.namespace, project)
         set_protected_branch_name('master')
         within('.new_protected_branch') do
-          find(".js-allowed-to-push").click
+          allowed_to_push_button = find(".js-allowed-to-push")
+
+          unless allowed_to_push_button.text == access_type_name
+            allowed_to_push_button.click
             within(".dropdown.open .dropdown-menu") { click_on access_type_name }
           end
+        end
         click_on "Protect"
 
         expect(ProtectedBranch.count).to eq(1)
@@ -124,9 +128,13 @@ feature 'Projected Branches', feature: true, js: true do
         visit namespace_project_protected_branches_path(project.namespace, project)
         set_protected_branch_name('master')
         within('.new_protected_branch') do
-          find(".js-allowed-to-merge").click
+          allowed_to_merge_button = find(".js-allowed-to-merge")
+
+          unless allowed_to_merge_button.text == access_type_name
+            allowed_to_merge_button.click
             within(".dropdown.open .dropdown-menu") { click_on access_type_name }
           end
+        end
         click_on "Protect"
 
         expect(ProtectedBranch.count).to eq(1)