cJSON_SetNumberValue: Fix compiler warning with -Waddress

cJSON.h

@@ -173,7 +173,7 @@ extern void cJSON_Minify(char *json);
 #define cJSON_SetIntValue(object, number) ((object) ? (object)->valueint = (object)->valuedouble = (number) : (number))
 /* helper for the cJSON_SetNumberValue macro */
 extern double cJSON_SetNumberHelper(cJSON *object, double number);
-#define cJSON_SetNumberValue(object, number) ((object) ? cJSON_SetNumberHelper(object, (double)number) : (number))
+#define cJSON_SetNumberValue(object, number) ((object != NULL) ? cJSON_SetNumberHelper(object, (double)number) : (number))
 
 /* Macro for iterating over an array */
 #define cJSON_ArrayForEach(pos, head) for(pos = (head)->child; pos != NULL; pos = pos->next)