fix wrapping of line in CHANGES.txt

CHANGES.txt

diff --git a/CHANGES.txt b/CHANGES.txt
index 4a80c17..f4c9eaf 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -22,7 +22,8 @@
     on an error path.
   * Avoid expensive inlined code space for encoding message length for messages
     >= 128 bytes and instead do a procedure call to a shared out-of-line routine.
-  * util::DefaultFieldComparator will be final in a future version of protobuf. Subclasses should inherit from SimpleFieldComparator instead.
+  * util::DefaultFieldComparator will be final in a future version of protobuf.
+    Subclasses should inherit from SimpleFieldComparator instead.
 
   Java:
   * Detect invalid overflow of byteLimit and return InvalidProtocolBufferException as documented.