Restore png_combine_row() to progressive-read-only builds.

CHANGES

diff --git a/CHANGES b/CHANGES
index 4d4e5f3..3674958 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2132,8 +2132,8 @@
   Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
 
 version 1.4.0beta60 [May 18, 2009]
-  Conditionally compile png_combine_row() and png_read_finish_row()
-    which are not used by progressive readers.
+  Conditionally compile png_read_finish_row() which is not used by
+    progressive readers.
 
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.