Ignore post_max_size when it's disabled
Ignore post_max_size when it's disabled

Resolves issue #3081
MichaelMaar/concrete5,TimDix/concrete5,avdevs/concrete5,matt9mg/concrete5,avdevs/concrete5,avdevs/concrete5,MichaelMaar/concrete5,matt9mg/concrete5,MichaelMaar/concrete5,TimDix/concrete5,matt9mg/concrete5,TimDix/concrete5