Don't try to split a tuple for debug output

[keis]

Add tuple to the list of types that should not be split()

[arthepsy]

LGTM. Anyhow, can You elaborate in what situation this happens?

[keis]

It happens when trying to use webauthn with debug on

!!! Touch the flashing U2F device to authenticate... !!!
Traceback (most recent call last):
  File "/home/keis/src/github.com/arthepsy/pan-globalprotect-okta/./gp-okta.py", line 660, in okta_mfa_webauthn
    dbg(conf.debug, 'assertion.result', result)
  File "/home/keis/src/github.com/arthepsy/pan-globalprotect-okta/./gp-okta.py", line 130, in dbg
    for line in x.split('\n'):
AttributeError: 'tuple' object has no attribute 'split'

This is with fido2==0.7.0 so before the API change that's mentioned in #33

[coldcoff]

@arthepsy: That change is good. It's useful for #33 but unrelated.

[coldcoff]

@arthepsy -- please merge.