hgweb: fill {rename} even if ?linerange is specified

Otherwise, {rename % ...} would fail.

Hopefully this is the last hgweb patch so I can start fixing templater
stuff.

mercurial/hgweb/webcommands.py

@@ -1097,6 +1097,7 b' def filelog(web):'
                 'file': path,
                 'diff': diffs,
                 'linerange': webutil.formatlinerange(*lr),
+                'rename': templateutil.mappinglist([]),
             })
             entries.append(lm)
             if i == revcount: