code: def permit_gitrepo(config_fpath, writeback=False):
      
      # Define search replace patterns
      username_regex = utool.named_field('username', utool.REGEX_VARNAME)
      username_repl = utool.backref_field('username')
      regexpat = r'https://github.com/' + username_regex + '/'
      replpat = r'git@github.com:' + username_repl + '/'
      # Read and replace
      lines = utool.read_from(config_fpath, aslines=True)
      newlines = utool.regex_replace_lines(lines, regexpat, replpat)
      # Writeback or print
      if not WRITEBACK:
          print(''.join(newlines))
      else:
          utool.write_to(config_fpath, newlines, aslines=True)
docs: Changes https:// in .git/config files to git@ and makes
      appropriate changes to colons and slashses