Fix for grayscale images (#20506)

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/fop-0_20_2-maintain@196494 13f79535-47bb-0310-9956-ffa450edef68

CHANGES

@@ -1,5 +1,7 @@
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 Done since 0.20.4 release
+- Fix for bug #20506 (grayscale images in PS renderer) (JM)
+  Submitted by: Zhong(George) Yi <yidaomao@yahoo.com>
 - Fix for bad font encodings in the PS renderer (Fonts get reencoded as
   WinAnsiEncoding, Symbol and ZapfDingbats show correctly now) (JM)
   Financed by: CTB/McGraw-Hill