[#733] morph: Fix delete container signature check

Committed invalid condition, it was just for debug.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/morph/client/container/delete.go

@@ -67,7 +67,7 @@ func (d *DeletePrm) SetKey(key []byte) {
 //
 // If TryNotary is provided, calls notary contract.
 func (c *Client) Delete(p DeletePrm) error {
-	if len(p.signature) == 0 && p.IsControl() {
+	if len(p.signature) == 0 && !p.IsControl() {
 		return errNilArgument
 	}