Fix missing close quote in error message

Do not strip single quotes from the exception message in the function add_coloring_to_emit_ansi in _logging.py.

For reasons that probably were sensible at the time (I guess), leading and trailing single quotes were stripped from the exception message. This was done to avoid error strings like KeyError: 'missing_key', but I think it's better to not touch this string.

Closes RAP-752