hgweb: fix {diff} expansion in JSON template
The same sort of bug as the previous patch. In this case, I decided to fix
the JSON template since we aren't ready to fix the {diff} keyword without BC.
I'll rework it later.
--- a/mercurial/templates/json/map Sun Mar 18 21:35:43 2018 +0900
+++ b/mercurial/templates/json/map Sun Mar 18 21:46:20 2018 +0900
@@ -142,7 +142,7 @@
"author": {author|utf8|json},
"parents": [{join(parent%changesetparent, ", ")}],
"children": [{join(child%changesetparent, ", ")}],
- "diff": [{join(diff%diffblock, ", ")}]
+ "diff": [{join(diff, ", ")}]
}'
diffblock = '\{
"blockno": {blockno|json},