Fix typo on the audit logs.
Fix typo on the audit logs.

It is not _serverity_. Renamed to severity. Details on issue: #1114

wafbuild/ModSecurity,defanator/ModSecurity,defanator/ModSecurity,SpiderLabs/ModSecurity,SpiderLabs/ModSecurity,SpiderLabs/ModSecurity,wafbuild/ModSecurity,wafbuild/ModSecurity,defanator/ModSecurity