Fix the `sync` function getting stuck by the `getPeer` (#109)
Fix the `sync` function getting stuck by the `getPeer` (#109)

* [payment] add a maximum retry time for `getPeer` function to fix inappropriate stuck of `sync` function

* [payment] re-write the getPeer in channel so that the sync function will not be blocked by getPeer anymore

bitmark-inc/bitmarkd,bitmark-inc/bitmarkd