http: handle 'match all' rule correctly
http: handle 'match all' rule correctly

To handle 'match all' rule correctly, we need to return a handler
unconditionally when no URL added to the rule.

Fixes #821

Closes #822

scylladb/seastar,avikivity/seastar,avikivity/seastar,dreamsxin/seastar,syuu1228/seastar,dreamsxin/seastar,avikivity/seastar,syuu1228/seastar,cloudius-systems/seastar,scylladb/seastar,cloudius-systems/seastar,cloudius-systems/seastar,syuu1228/seastar,scylladb/seastar,dreamsxin/seastar