PHP 7.3 compatibility issue

Reviewed, the fix looks good, but I wouldn't add additional documentation explaining that the line needs to be at the top. That context is only useful for people looking at this particular issue, but for future readers of the code this is not useful at all.

Setting this to minor since this seems to be a false positive from the PHPCompatibility library. The $hook_base variable isn't changed by reference in the preceding lines, but there's no way that PHPCompatibility can know that for sure in procedural function calls, so it reports this.

It would be good to get this fix in anyway to make the warning go away.

Quick update of this one liner. It it quiet the assumed false positive, lets get it in.

How is this not in yet?