wix: restore COPYING.rtf
This got truncated to 0 bytes in 0ab651b5f77c when the Phabricator extension
crashed because it's a binary file. That caused the license page in the WIX
installer to be empty. I don't remember if I needed to resubmit after the bug
was fixed, so let's try this again with the current stable. If this fails, I'll
retry with 5.1 to see if this is a regression in the API changeover last cycle.
Differential Revision: https://phab.mercurial-scm.org/D8052
https://bz.mercurial-scm.org/1089
$ hg init
$ mkdir a
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ hg ci -m m a
$ mkdir a b
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ cd b
Relative delete:
$ hg ci -m m ../a
$ cd ..