Mark the "val" variable in json_object_object_foreach as unused so the compiler doesn't complain. Fix warnings in the testReplaceExisting test.
diff --git a/json_object.h b/json_object.h
index c97850a..e18af8a 100644
--- a/json_object.h
+++ b/json_object.h
@@ -309,7 +309,7 @@
# define json_object_object_foreach(obj,key,val) \
char *key; \
- struct json_object *val; \
+ struct json_object *val __attribute__((__unused__)); \
for(struct lh_entry *entry ## key = json_object_get_object(obj)->head, *entry_next ## key = NULL; \
({ if(entry ## key) { \
key = (char*)entry ## key->k; \