webcommands: use pycompat.strkwargs as needed

Differential Revision: https://phab.mercurial-scm.org/D2305

mercurial/hgweb/webcommands.py

@@ -561,7 +561,7 b' def manifest(web, req, tmpl):'
                 fentries=filelist,
                 dentries=dirlist,
                 archives=web.archivelist(hex(node)),
-                **webutil.commonentry(web.repo, ctx))
+                **pycompat.strkwargs(webutil.commonentry(web.repo, ctx)))
 
 @webcommand('tags')
 def tags(web, req, tmpl):