Do not quite when `pumactl` unexpectedly exits.
Do not quite when `pumactl` unexpectedly exits.

When `pumactl` encounters issue, it exits [[1]]. That way also the whole
test suite unexpectedly exits. Rescuing `SystemExit` exception keeps the
test suite finish.

Fixes #2329

[1]: https://github.com/puma/puma/blob/0f718d516b92cd8bc4120c543b06792b22ac20bb/lib/puma/control_cli.rb#L272

puma/puma,puma/puma,eileencodes/puma,eileencodes/puma,puma/puma,eileencodes/puma,eileencodes/puma,puma/puma