[rilmodem] do not check spdi if mcc and mnc are not valid

It is possible that network is received before current operator
is retrieved. In rare occasions this causes crash when tried
to compare mnc and mcc of current operator to spdi.

Signed-off-by: Jussi Kangas <jussi.kangas@oss.tieto.com>
Merge pull request #113 from jkangas/master

Request for pulling mcc and mnc presence check before spdi search to main branch
[rilmodem] numeric value can be null in response to RIL_REQUEST_OPERATOR

According to ril.h numeric value can be null in response to
RIL_REQUEST_OPERATOR. That means phone is unregistered and
current operator should return error

Signed-off-by: Jussi Kangas <jussi.kangas@oss.tieto.com>
Merge pull request #114 from jkangas/master

Request for pulling operator name numeric value check to main branch