be more forgiving in configured dns names

[icing]

ServerName and ServerAlias names may carry port numbers, as in greenbytes.de:443 and mod_md needs to strip those silently when matching MDs against vhosts.

[randolf]

The ServerName does support that, but according to the documentation the ServerAlias directive does not:

https://httpd.apache.org/docs/2.4/mod/core.html#serveralias

[icing]

You are correct. The ServerName needs to be normalized in checks.