Configuration breaks with long header names

[hgascoigne]

The most recent version breaks when provided with header names longer than 32 characters. For example, we are using Content-Security-Policy-Report-Only and serve will not start:

INFO: Discovered configuration in `serve.json`
ERROR: The configuration you provided is wrong:
should NOT be longer than 32 characters
{"limit":32}

[leo]

Oh, indeed. That's definitely too short, I'm sorry! I'll make sure to extend it in a moment.

[hgascoigne]

No worries, thanks for taking a look!

[leo]

Works now!