Fatal Error Fix: Remove unnecessary comma that causes a site-wide fatal server error on PHP 7.2

[KZeni]

I'm going to be a bit brief on these details as this is a hot issue needing a hot fix.

I've started a support forum topic on this at https://wordpress.org/support/topic/fatal-error-php-7-2-syntax-error-breaking-whole-site-3/ for further discussion/reference/etc. as well.

[KZeni]

Created an issue at #548 just in case that's helpful for reference & as a more complete reporting of things (WP.org support forum + GH issue + GH PR.)

[KZeni]

Just in case it helps speed up the release of the hotfix, I made an additional edit to update the 3 times the version is mentioned in readme.txt & two-factor.php from 0.8.0 to 0.8.0.1 since this really is a hotfix for this one previous release.

[iandunn]

Thanks for finding this and helping out with a quick PR!

I don't have a 7.2 box readily available for testing, but I'm assuming it works on your end. The diff looks good and tests fine on 8.0

I removed the version bump, since we do that during the release process.

#461 should add automated version testing

[iandunn]

@KZeni 0.8.1. is now available on wordpress.org. Please let me know if you run into any issues installing it or after.