Some small cleanups for convert extension:
- repo doesn't need to be imported
- util.Abort doesn't need \n
- space after comma
- long lines
- spacing
abort: repository a not found!
255
abort: error: Connection refused
255
abort: repository a not found!
255
abort: destination '../a' already exists
255
abort: repository a not found!
255
destination directory: q
abort: destination 'q' already exists