hgweb: use sysstr to get attribute on diff option
Attribute identifier should be `str` not `bytes`.
== New Features ==
* Windows will process hgrc files in %PROGRAMDATA%\Mercurial\hgrc.d.
== New Experimental Features ==
== Bug Fixes ==
* The `indent()` template function was documented to not indent empty lines,
but it still indented the first line even if it was empty. It no longer does
that.
== Backwards Compatibility Changes ==
== Internal API Changes ==
* Matcher instances no longer have a `explicitdir` property. Consider
rewriting your code to use `repo.wvfs.isdir()` and/or
`ctx.hasdir()` instead. Also, the `traversedir` property is now
also called when only `explicitdir` used to be called. That may
mean that you can simply remove the use of `explicitdir` if you
were already using `traversedir`.
* The `revlog.nodemap` object have been merged into the `revlog.index` object.
* `n in revlog.nodemap` becomes `revlog.index.has_node(n)`,
* `revlog.nodemap[n]` becomes `revlog.index.rev(n)`,
* `revlog.nodemap.get(n)` becomes `revlog.index.get_rev(n)`.
* `copies.duplicatecopies()` was renamed to
`copies.graftcopies()`. Its arguments changed from revision numbers
to context objects. It also lost its `repo` and `skip` arguments
(they should no longer be needed).