Ensure we use strict JSON when determining if we're using a JSON format.
This fixes a regression in parsing Google Cloud Storage or possibly
other non-JSON formats.
Fixes
@@ -699,6 +699,8 @@ is_json_log_format (const char *fmt) {
json_stream json;
json_open_string (&json, fmt);
+ /* ensure we use strict JSON when determining if we're using a JSON format */
+ json_set_streaming (&json, false);
do {
t = json_next (&json);
switch (t) {
