chsmack: less error printing
chsmack: less error printing

Is it really an error to remove an attribute
that doesn't exists? I don't think so because
the final result is the expected result.

Signed-off-by: José Bollo <08496fd66cc394b517cafa0b18bcb9ce79fe4230@iot.bzh>

jobol/smack,jobol/smack,smack-team/smack,smack-team/smack