fix bug when vid not found

fix https://github.com/seaweedfs/seaweedfs/issues/4193

weed/shell/command_ec_encode.go

@@ -99,7 +99,7 @@ func doEcEncode(commandEnv *CommandEnv, collection string, vid needle.VolumeId,
 
 	// find volume location
 	locations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
-	if !found && len(locations) > 0 {
+	if !found {
 		return fmt.Errorf("volume %d not found", vid)
 	}