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.
% initialize repository
adding a
% try hgweb request
0
1f424bb22ec05c3c6bc866b6e67efe43 page1