PHP crash message not logged

[adamziel]

@wojtekn reported in #470 that this happens since the PR was merged:

I also noticed that now it doesn't log the exit message from PHP, which was zend_mm_heap corrupted.

The exit message was visible in #416 (comment). Let's make sure it remains visible to the developer.

[adamziel]

The original issue is no longer reproducible and the error reporting was greatly improved since then. I'm closing this one for now. Let's reopen if the original problem and poor logging ever reemerges.