Remove trivial comments

k9mail/src/androidTest/java/com/fsck/k9/activity/MessageReferenceTest.java

@@ -71,7 +71,6 @@ public class MessageReferenceTest {
 
     @Test
     public void equalsWithAnObjectShouldReturnFalse() {
-        // null : creating a new empty MessageReference
         MessageReference messageReference = new MessageReference(null, null, null, null);
         Object object = new Object();
 

k9mail/src/main/java/com/fsck/k9/activity/MessageReference.java

@@ -60,7 +60,7 @@ public class MessageReference implements Parcelable {
         if (identity == null || identity.length() < 1) {
             throw new MessagingException("Null or truncated MessageReference identity.");
         }
-        // Some temp variables
+
         String accountUuid = null;
         String folderName = null;
         String uid = null;