Revert "For the common case of "getMessage" where we actually have the object in"

This doesn't work on initial sync, since the comparisons fail and you're
left with duplicates in the displayed mailbox
This reverts commit fa1c88bec348d0132acc60a320626bf0ca1170ec.

src/com/fsck/k9/activity/MessageList.java

@@ -2396,19 +2396,7 @@ public class MessageList
         }
         public MessageInfoHolder getMessage(Message message)
         {
-
-            synchronized (mAdapter.messages)
-            {
-                int index = mAdapter.messages.indexOf(message);
-                if (index == -1)
-                {
-                    return null;
-                }
-                else
-                {
-                    return mAdapter.messages.get(index);
-                }
-            }
+            return getMessage(message.makeMessageReference());
         }
 
         // XXX TODO - make this not use a for loop