`gq -v key=value` does not accept '=' in the value.

[ppdx999]

Thank you for developing this library. I'm grateful for your work.

When I run the command gq ${endpoint} -q {query} -v "key=YmFzZTY0IGVuY29kZWQ=", it fails with the following error:

Error: cannot parse variable 'key=YmFzZTY0IGVuY29kZWQ= (multiple '=')'

I'm pleased that I can pass a base64-encoded value using the 'v' option.