prevent false detection of opendkim KeyTable config

default /etc/opendkim.conf has KeyTable appear in comment doco and example.
Shouldn't trigger the grep that checks whether this config has been applied.

Fix typo in the deleting of `-o` flags

Deleting all settings starting with o seems rather arbitrary, but I don't know the default configuration on Vultr, so could be warranted :) But I'll be bold and guess the `sed` command and the following lines are supposed to be related?