Add a helper method.

res/com/dmdirc/ui/messages/format.yml

@@ -129,7 +129,7 @@ ChannelKickEvent:
              {{channel.name}}{{reason|bracketed}}.
   colour: 3
 ChannelUserAwayEvent:
-  format: "-- {{user.modePrefixedNickname}} is now away{{reason|bracketed}}."
+  format: "-- {{user.modePrefixedNickname}} is now away{{reasonOrBlank|bracketed}}."
   colour: 14
 channelUserBackEvent:
   format: "-- {{user.modePrefixedNickname}} is now back."

src/com/dmdirc/events/ChannelUserAwayEvent.java

@@ -61,4 +61,8 @@ public class ChannelUserAwayEvent extends ChannelUserEvent {
         return reason;
     }
 
+    public String getReasonOrBlank() {
+        return reason.orElse("");
+    }
+
 }