obsolete: fix ValueError when stored note contains ':' char (issue5783) The newer version of `amend -n 'Some some'` accepts containing ':' char. The information contained in this note 'Testing::Obstore' gives ValueError, because we are trying to store more than 2 values in key and value. Differential Revision: https://phab.mercurial-scm.org/D4883 Differential Revision: https://phab.mercurial-scm.org/D4882