Miscellaneous code cleanups.

briar-api/src/main/java/org/briarproject/briar/api/blog/MessageType.java

@@ -7,7 +7,7 @@ public enum MessageType {
 	WRAPPED_POST(2),
 	WRAPPED_COMMENT(3);
 
-	int value;
+	final int value;
 
 	MessageType(int value) {
 		this.value = value;

briar-api/src/main/java/org/briarproject/briar/api/privategroup/event/GroupMessageAddedEvent.java

@@ -40,6 +40,7 @@ public class GroupMessageAddedEvent extends Event {
 		return text;
 	}
 
+	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
 	public boolean isLocal() {
 		return local;
 	}