bookmarks: break long line found by check-code

hgext/bookmarks.py

@@ -451,7 +451,8 b' def push(oldpush, ui, repo, dest=None, *'
                 ui.status(_("deleting remote bookmark %s\n") % b)
                 new = '' # delete
             else:
-                ui.warn(_('bookmark %s does not exist on the local or remote repository!\n') % b)
+                ui.warn(_('bookmark %s does not exist on the local '
+                          'or remote repository!\n') % b)
                 return 2
             old = rb.get(b, '')
             r = other.pushkey('bookmarks', b, old, new)