shell: fix moving volume, volume server evacuate

fix https://github.com/chrislusf/seaweedfs/issues/1534

weed/shell/command_volume_server_evacuate_test.go

@@ -0,0 +1,17 @@
+package shell
+
+import (
+	"os"
+	"testing"
+)
+
+func TestVolumeServerEvacuate(t *testing.T) {
+	topologyInfo := parseOutput(topoData)
+
+	volumeServer := "192.168.1.4:8080"
+
+	if err := evacuateNormalVolumes(nil, topologyInfo, volumeServer, true, false, os.Stdout); err != nil {
+		t.Errorf("evacuate: %v", err)
+	}
+
+}