Enable audit log by default

[peterkeung]

• We eventually enable the audit log for most clients
• The audit log usually gets enabled after something bad has happened (and at that point we waste a bunch of time trying to analyze the Apache logs)
• There are only positives to having the audit log enabled
• The log files automatically rotate, so there isn't additional configuration that we need to remember

[pkamps]

+1

[benkmugo]

+1

[peterkeung]

Equivalent PR in the eZ Publish repo, which at the time of this writing has not been merged: ezsystems#1267