The first letter should be small in errors.New

Signed-off-by: YuPengZTE <yu.peng36@zte.com.cn>

integration-cli/docker_utils.go

@@ -519,7 +519,7 @@ func validateArgs(args ...string) error {
 			foundBusybox = key
 		}
 		if (foundBusybox != -1) && (key == foundBusybox+1) && (strings.ToLower(value) == "top") {
-			return errors.New("Cannot use 'busybox top' in tests on Windows. Use runSleepingContainer()")
+			return errors.New("cannot use 'busybox top' in tests on Windows. Use runSleepingContainer()")
 		}
 	}
 	return nil