php upgrade causes warnings

Having looked at the file causing the warning, I note that the 'continue' at line 426, unlike all the other examples, does not have a '2' following:
425 if ( $groupUser->get( 'id' ) ) {
426 continue;
427 }
I've added that 2 and the warning no longer shows. Is this the solution? ( I no longer use groupjive and have the plug-in disabled)

Ah, looks like we missed a continue statement in the fix. Change "continue;" to "continue 2;" to resolve it. Will fix for next build.

OK, glad we've identified that ; is there some way whereby users can get notice of these 'builds'?

Yes, there's several ways. One is to check our releases page now and again. You can find this page below.

www.joomlapolis.com/news/releases

Another is our version checker module which should already be on the control panel of your Joomla backend. If not it was unpublished and you'll need to publish it again. There's also the version checker in CB > Plugin Management where a version will turn red if there's a new release. You can also check within CB > Plugin Management > Install New Plugin > Install from Web for new releases. Note all version checking has a cache time of 24 hours so if a release is made after a version check has been cached you won't be notified until 24 hours later. The exception is Install from Web which you can manually refresh (link is bottom right of its tab).