hgweb: handle exception of misconfigured path on index page
If hgweb.config contains wrong path mapping, hgweb causes internal server
error on repository index page.
This patch changes makeindex() to ignore RepoError, because it looks to be
designed to suppress configuration error.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "hgk=" >> $HGRCPATH
hg init repo
cd repo
echo a > a
hg ci -Am adda
hg debug-cat-file commit 0