chg: silence warning of unused parameter 'sig'

hgweb: reindent atom/changelogentry.tmpl It was mixing tabs and spaces, and not in a good way. Indent style of other atom entries seems to be 1 space per level, so let's apply it here as well.

hgweb: remove unused/nonexistent filelogentry from atom/map filelog in atom style uses changelogentry to show commits, and atom/filelogentry.tmpl doesn't even exist.