Merge pull request #683 from csmith/master

Fix NPE in ShowTopic...

src/com/dmdirc/commandparser/commands/channel/ShowTopic.java

@@ -77,7 +77,7 @@ public class ShowTopic extends Command implements ExternalCommand {
                 final User user = topic
                         .flatMap(Topic::getClient)
                         .map(GroupChatUser::getUser)
-                        .orElseGet(null);
+                        .orElse(null);
                 channel.getEventBus().publishAsync(
                         new ChannelGotTopicEvent(channel, topic.get(), user));
             } else {