Remove check that there are no commas in the DN.
Remove check that there are no commas in the DN.

- As commas are allowed in an IGTF DN, just not in the `DC` part.
- The subsequent check that the DN begins with a slash should
  be sufficient to ensure DNs aren't in the comma separated format.

tofu-rocketry/apel,apel/apel,tofu-rocketry/apel,apel/apel