Bug 861725 (follow-up) - Correct the logic of checking call forwarding reason. r=vicamo

We don't support A_CALL_FORWARDING_REASON_ALL and A_CALL_FORWARDING_REASON_ALL_CONDITIONAL
for now, because there is no detailed information about how to handle these two types in TS 22.082.

So it should be

if (reason == A_CALL_FORWARDING_REASON_ALL || reason == A_CALL_FORWARDING_REASON_ALL_CONDITIONAL) {
    ....
    return "+CME ERROR: 50";
}