eth-watcher: allow peers to unconfigured watchdogs
We simply respond with an empty history. This allows applications to
safely subscribe prior to a watchdog's creation.
:+ %diff %eth-watcher-diff
:- %history
^- loglist
- ~| [%no-such-watchdog t.path]
- (zing history:(~(got by dogs.state) t.path))
+ (zing history:(~(gut by dogs.state) t.path *watchdog))
(pure:m state)
::
:: +handle-peek: get diagnostics data
