Fix 'x' command processing in mod_sed.

This has been tested using a slighly modified example taken from:
    https://blogs.oracle.com/basant/entry/using_mod_sed_to_filter
(OutputSed "s/.\*//"             has been changed in                OutputSed "s/.*//")

OutputSed "/Sunday/ {"
OutputSed "h"
OutputSed "s/.*//"
OutputSed "N"
OutputSed "s/\^.//"
OutputSed     "/Monday/ {"
OutputSed         "x"
OutputSed         "s/Sunday/Monday/"
OutputSed         "x"
OutputSed         "s/Monday/Tuesday/"
OutputSed         "H"
OutputSed         "g"
OutputSed     "}"
OutputSed "}"

Add CHANGES entry for r1749401
Submitted by: jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1750481 13f79535-47bb-0310-9956-ffa450edef68