stratum: parse_notify(): Don't die on malformed bbversion/prev_hash/nbit/ntime.

Might have introduced a memory leak, don't have time to check. :(

Should the other hex2bin()'s be checked?

Thanks to Mick Ayzenberg <mick.dejavusecurity.com> for finding this.
void _cgsem_wait(cgsem_t *cgsem, const char *file, const char *func, const int line)
{
retry:
	if (unlikely(sem_wait(cgsem))) {
		if (interrupted())
			goto retry;
		quitfrom(1, file, func, line, "Failed to sem_wait errno=%d cgsem=0x%p", errno, cgsem);
	}
}

void _cgsem_wait(cgsem_t *cgsem, const char *file, const char *func, const int line)
{
retry:
	if (unlikely(sem_wait(cgsem))) {
		if (interrupted())
			goto retry;
		quitfrom(1, file, func, line, "Failed to sem_wait errno=%d cgsem=0x%p", errno, cgsem);
	}
}
