erasure coding: tracking encoded/decoded volumes

If an EC shard is created but not spread to other servers, the masterclient would think this shard is not located here.

weed/shell/command_ec_encode.go

@@ -95,7 +95,7 @@ func (c *commandEcEncode) Do(args []string, commandEnv *CommandEnv, writer io.Wr
 func doEcEncode(commandEnv *CommandEnv, collection string, vid needle.VolumeId, parallelCopy bool) (err error) {
 	// find volume location
 	locations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
-	if !found {
+	if !found && len(locations) > 0 {
 		return fmt.Errorf("volume %d not found", vid)
 	}