Z-Push 2.4.3 final release

Hello, we have just released Z-Push 2.4.3 final (tag 2.4.3 commit db9535be7940d0d0c83e1e08de77bd40997398f3). This is a maintenance release with some bugfixes and improvements. This is the first Z-Push release which supports PHP 7.2 (default PHP version in Ubuntu...