plugins: ublox: bearer: SIM absence should not break disconnect

If we have a modem with an established connection, and then the
SIM is getting removed from that modem, this forces modem reprobing
sequence.

It looks like that:
```
 mm-base-modem:mm_base_modem_process_sim_event
 -> mm-base-modem:mm_base_modem_disable
 -> mm-base-modem:disable
 -> mm-broadband-modem:common_disable
 -> mm-broadband-modem:disabling_step,
 -> ctx->step=DISABLING_STEP_FIRST
 -> ctx->step=DISABLING_STEP_WAIT_FOR_FINAL_STATE
 -> ctx->step=DISABLING_STEP_DISCONNECT_BEARERS
```

At this stage, there is no actual connection existing already, but
bearer objects still exist and are still marked as connected.
So, if there were any active bearers - they will be disconnected.

In order to disconnect, ublox bearer sends +CGACT=0,%u, modem then
will return CME ERROR: 10(SIM not inserted):
```
[modem0/ttyACM0/at] --> 'AT+CGACT=0,1<CR>'
[modem0/ttyACM0/at] <-- '<CR><LF>+CME ERROR: 10<CR><LF>'
[modem0/ttyACM0/at] operation failure: 10 (SIM not inserted)
[modem0/bearer0] couldn't disconnect: SIM not inserted
```
this error will break disabling and reprobing. To fix that, it's
require to add 'SIM not inserted' state as a valid condition to
continue bearer disconnection.

0 files changed, 0 insertions, 0 deletions