Some modems do not support CSIM lock/unlock, but they do support
querying SIM unlock retries through +CSIM command.
If CSIM lock returns with "unsupported command" do not propagate
the error and continue with the other CSIM queries instead, moreover the
CSIM lock feature is signed as FEATURE_UNSUPPORTED in Telit modem
private structure to prevent being sent again (e.g. calling CSIM
unlock AT command).
Carlo Lobrano
Dan Williams