statichttprepo: explicitly convert error message to str (
issue6247)
For Python 2.7, the implicit conversion of the HTTPError instance to
str was good enough. For Python 3.x, this fails later when hitting the
str to bytes conversion logic.
Differential Revision: https://phab.mercurial-scm.org/D9661
<?xml version="1.0" encoding="{encoding}"?>
<rss version="2.0">
<channel>
<link>{urlbase}{url|urlescape}</link>
<language>en-us</language>