Merge r1429564 from trunk:

Use ap_bin2hex instead of sprintf(..., "%02x". It gives the same output and is faster.

No real speedup should be achieved on production machine, because this is done
only for characters that need to be escaped. 
However, this will close PR 50919.

Submitted by: jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1455222 13f79535-47bb-0310-9956-ffa450edef68