Work around infinite memory consumption bug. CRM-17853

Work around infinite memory consumption bug. CRM-17853

When handling an Unhandled exception, the default error handler path uses debug_var to handle outputting debug information. When calling debug_var, no print argument is passed. Without a print argument, debug_var uses print_r to dump a passed in variable's contents. This consumes all memory, and leads to a crash (500). passing a different option to debug_var works around the issue.