debian/changelog: advertise "xzgrep -q pattern file" fix

In v5.0.4~26 (Fix exit status of xzgrep when grepping binary files,
2012-02-22), xzgrep -q, xzgrep -l, and other commands that cause grep
to exit before the decompressor has finished writing its output
learned to use the exit status from grep instead of the decompressor
when unxz or bunzip2 dies with SIGPIPE.
1 file changed