Infinite recursion happened in the ENOMEM error case and eventually led to a stack overflow. To avoid recursion, bypass full g_log() and call _g_log_fallback_handler() directly.
Also append a newline in _g_log_fallback_handler(), so that we don't print (all on one line):
gprintf.c:348: failed to allocate memoryAborted (core dumped)
Fixes #2753 (closed)