YKCS11: more elaborate solution for stripping DER encoding from ECDSA signatures.

It is possible to receive different padding length for r and s, where their length
is [-1, 1] wrt the component lenght. Take this into account.

ykcs11/ykcs11.c

@@ -1783,6 +1783,9 @@ CK_DEFINE_FUNCTION(CK_RV, C_Sign)(
     return CKR_OK;
   }
 
+  fprintf(stderr, "MI HAI DATO %lu!!!!!!!!!!!!!!!!!!!!!\n", *pulSignatureLen);
+
+
   DBG("Sending %lu bytes to sign", ulDataLen);
 #if YKCS11_DBG == 1
   dump_hex(pData, ulDataLen, stderr, CK_TRUE);