CDRIVER-2250 nModified is not available in MongoDB 2.4

Author: bjori

tests/test-mongoc-collection.c

@@ -506,6 +506,11 @@ test_insert_null (void)
    bson_iter_t iter;
    uint32_t len;
 
+   /* nModified isn't available in 2.4 */
+   if (!test_framework_max_wire_version_at_least (2)) {
+      return;
+   }
+
    client = test_framework_client_new ();
    ASSERT (client);
 
@@ -556,6 +561,7 @@ test_insert_null (void)
    ASSERT_OR_PRINT (ret, error);
    ret = mongoc_bulk_operation_execute (bulk, &reply, &error);
    ASSERT_OR_PRINT (ret, error);
+
    ASSERT_MATCH (&reply,
                  "{'nInserted': 0,"
                  " 'nMatched':  1,"