adding error message to manage roles page when no teams have been created
Fixes NPE related to not all defect trackers returning dynamic form fields.
Merge pull request #579 from denimgroup/bugfix-tfgl69-add-error-msg-to-manage-roles-page

adding error message to manage roles page when no teams have been create...
Merge commit 'd3cf203e5e917bf63759d479538fa9c8aea4afde' into HEAD