Add missing CODEC-121 to release notes.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1637108 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

RELEASE-NOTES.txt

@@ -15,6 +15,8 @@ New features:
 
 o Add Daitch-Mokotoff Soundex  
   Issue: CODEC-192. Thanks to Thomas Neidhart. 
+o QuotedPrintableCodec does not support soft line break per the 'quoted-printable' example on Wikipedia
+  Issue: CODEC-121. Thanks to Thomas Neidhart, Java John.
 o Make possible to provide padding byte to BaseNCodec in constructor  
   Issue: CODEC-181. Thanks to Ivan Martinez-Ortiz.