tests/test-hgweb-raw.out

tests: don't match blank output lines as regexes in unified tests

Currently, the following unified test will pass:

  $ echo foo


A blank output line (a line containing just two spaces) will match any
output.

The patch modifies the unified test runner to ignore empty strings
strings when do regular expression matching.

200 Script output follows
content-type: text/plain; charset="ascii"
content-length: 157
content-disposition: inline; filename="some \"text\".txt"

This is just some random text
that will go inside the file and take a few lines.
It is very boring to read, but computers don't
care about things like that.
host - - [date] "GET /?f=a23bf1310f6e;file=sub/some%20%22text%22.txt;style=raw HTTP/1.1" 200 -