Remove RELEASENOTES.docu files

They are no longer used after the move to Markdown based release-notes.

Author: aconradi

MODULEINFO

@@ -83,10 +83,7 @@ Require-tokens: public
 
 Group: dmlc
 Require-tokens: public
-Release-notes: src/tools/dmlc/RELEASENOTES.docu,
-               src/tools/dmlc/RELEASENOTES-1.2.docu,
-               src/tools/dmlc/RELEASENOTES-1.4.docu,
-               src/tools/dmlc/RELEASENOTES.md,
+Release-notes: src/tools/dmlc/RELEASENOTES.md,
                src/tools/dmlc/RELEASENOTES-1.2.md,
                src/tools/dmlc/RELEASENOTES-1.4.md
 Make: dmlc