Update release notes.

--HG--
branch : setuptools-0.6
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/branches/setuptools-0.6%4053328

setuptools.txt

@@ -2600,6 +2600,9 @@ XXX
 Release Notes/Change History
 ----------------------------
 
+0.6c6
+ * Fix not building binary RPMs correctly.
+
 0.6c5
  * Fix uploaded ``bdist_rpm`` packages being described as ``bdist_egg``
    packages under Python versions less than 2.5.