Move changelog entry to Unreleased

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 
 - Add system physical requirements section to INSTALL (#26937)
+- Warn when there is not enough disk space (#26937)
 
 ### Fixed
 
@@ -43,7 +44,6 @@ file)
 - Log line on start up with sbws version, platform info, and library versions
 (trac#26751)
 - Manual pages (#26926)
-- Warn when there is not enough disk space (#26937)
 
 ### Fixed