Don't add admins as masters to projects created in another user's namespace

Only admins have the ability to create a project in another user's personal
namespace. Prior to this commit, we were explicitly adding them as masters to
the project. However, admins already have access (by virture of being admins),
so this is unnecessary.

app/services/projects/create_service.rb

@@ -112,8 +112,7 @@ module Projects
       if group || @project.gitlab_project_import?
         current_user.refresh_authorized_projects
       else
-        owners = [current_user, @project.namespace.owner].compact.uniq
-        @project.add_master(owners, current_user: current_user)
+        @project.add_master(@project.namespace.owner, current_user: current_user)
       end
     end
 

spec/services/projects/create_service_spec.rb

@@ -38,7 +38,7 @@ describe Projects::CreateService, '#execute' do
 
       expect(project).to be_persisted
       expect(project.owner).to eq(user)
-      expect(project.team.masters).to include(user, admin)
+      expect(project.team.masters).to contain_exactly(user)
       expect(project.namespace).to eq(user.namespace)
     end
   end