Couple of SEGFAULTS - Null pointer dereference

[sravan0x00]

Hi,

In below code block of ngx_openidc_handler, variable ctx is NULL and this NULL pointer is de-referenced, causing SEGFAULT. I think it can be replaced with NGINX native logging function, until ctx is initialized properly.

	if (cfg == NULL) {
		oauth2_warn(ctx->log,
			    "ngx_http_get_module_loc_conf returned NULL");
		rv = NGX_ERROR;
		goto end;
	}
	ctx = oauth2_nginx_request_context_init(r);
	if (ctx == NULL) {
		oauth2_warn(ctx->log,
			    "openidc_nginx_request_context_init returned NULL");
		rv = NGX_ERROR;
		goto end;
	}

Thanks,
Sravan