YobiUpdate: Do not check update so frequently

By the default, Yobi checks whether new software update is available
every a millisecond. This is a bug of the configuration library to
interpret 1d as 1ms. See
lightbend/config#117 for detail of the bug.

conf/application.conf.default

@@ -141,7 +141,7 @@ application.notification.draft-time = 30s
 # Software Update
 # ~~~~~~~~~~~~~~~
 # Check for updates of Yobi at this interval if it is grater than 0.
-application.update.notification.interval = 1d
+application.update.notification.interval = 1h
 # A url to the git repository for Yobi releases.
 application.update.repositoryUrl = "http://repo.yobi.io/naver/yobi"
 # A format to construct the url to latest Yobi release. "%s" is a format