Revert "Issue #1923406 by stefan.r, yannickoo: Use ASCII character set on alphanumeric fields so we can index all 255 characters"

This reverts commit ac4e35ce.

Issue #1923406 by stefan.r, yannickoo: Use ASCII character set on alphanumeric fields so we can index all 255 characters

Patch #1161486 by rootatwc, sun, andypost, catch, marcingy, aspilicious, cam8001: Move IP blocking into its own module.