=act #16344 simple fix to stackoverflow on actor name validation

Simplest solution to the reported issue. I'd also like to try removing the regex (should have some time to do that), and see if there's a perf impact - the regex is rather simple so should be replacable with matching over a char array hm...

Removes matching of `\p{XDigit}	A hexadecimal digit: [0-9a-fA-F]`, which most likely shouldn't impact users.