Small text changes - trailing spaces and update year (#6022)

* remove trailing spaces

* update year

CHANGELOG.md

@@ -1,3 +1,3 @@
 # Mattermost Changelog
 
-Please see [Mattermost Team Edition Changelog](http://docs.mattermost.com/administration/changelog.html) in product documentation. 
+Please see [Mattermost Team Edition Changelog](http://docs.mattermost.com/administration/changelog.html) in product documentation.