Fix activesupport/CHANGELOG.md offense at 8-1-stable

This commit fixes the offense in activesupport/CHANGELOG.md.

```
$ tools/railspect changelogs .
..........E..

Offenses:

activesupport/CHANGELOG.md:7 Trailing whitespace detected.
    end
       ^
13 changelogs inspected, 1 offense detected
```

Follow up rails@f5266ee

Author: yahonda

activesupport/CHANGELOG.md

@@ -4,7 +4,7 @@
     ActiveSupport::Inflector.inflections(:en) do |inflect|
       inflect.acronym "USD"
       inflect.acronym "USDC"
-    end 
+    end
 
     "USDC".underscore # => "usdc"
     ```