Remove useless trailing spaces

[hywan]

There are some useless trailing spaces landing in the code. With a basic sed, we can remove all of them. The exact command line is the following:

$ sed -i '' -E 's/ +$//g' **/*.php

[hywan]

Whole patch

[johnbillion]

Thank you for your contribution, @hywan, but the WordPress project does not refactor code for the sake of it, for the reasons listed here: ​https://make.wordpress.org/core/handbook/contribute/code-refactoring/

[hywan]

Got it! Sorry for the noise.