api/config/channels/scan: add `dryRun` option.
api/config/channels/scan: add `dryRun` option.

Chinachu/Mirakurun,kanreisa/Mirakurun,Chinachu/Mirakurun,kanreisa/Mirakurun,Chinachu/Mirakurun,kanreisa/Mirakurun,Chinachu/Mirakurun