Currently, option arguments are only completed after =. For example:
$ btrbk --loglevel=<TAB>
debug error info trace warn
$ btrbk --loglevel <TAB>
archive diff extents ls prune run
stats clean dryrun list origin resume
snapshot usage
This commit makes it so that both option styles are recognized:
$ btrbk --loglevel=<TAB>
debug error info trace warn
$ btrbk --loglevel <TAB>
debug error info trace warn
This was the intention all along, but it was implemented incorrectly.