example code suffering from a double case of else-after-return simplified according to the subsequent rule

Fixes #6589: updated code style guide to mention else after return, adjusted code involved in the issue

issue #4719

```
vendor/bin/indent --spaces -r framework/
vendor/bin/indent --tabs -r . --pattern=*.json
vendor/bin/indent --spaces -r . --pattern=*.md
vendor/bin/indent --spaces -r . --pattern=yii.*.js
vendor/bin/indent --spaces -r . --pattern=*.css
```