[FAB-7928] Eventhub reg. unexpectedly fails

Eventhub registrations unexpectedly fail when peer.events.timewindow
is not set. This CR adds a default value of 15 minutes for the time
window to ensure that the peer does not default to 0 seconds, which
makes it impossible to register successfully.

Change-Id: I03b5ddda952bb4b62995f001202d94c7a7c262ee
Signed-off-by: Will Lahti <wtlahti@us.ibm.com>

peer/node/start.go

@@ -556,6 +556,12 @@ func initializeEventsServerConfig(mutualTLS bool) *producer.EventsServerConfig {
 		TimeWindow:       viper.GetDuration("peer.events.timewindow"),
 		BindingInspector: comm.NewBindingInspector(mutualTLS, extract)}
 
+	if ehConfig.TimeWindow == 0*time.Minute {
+		defaultTimeWindow := 15 * time.Minute
+		logger.Warningf("`peer.events.timewindow` not set; defaulting to %s", defaultTimeWindow)
+		ehConfig.TimeWindow = defaultTimeWindow
+	}
+
 	return ehConfig
 }