c1 cti after c1 pwr 0 does not work

The `c1 cti` command fails if it is issued after a `c1 pwr 0` command.

The variable(s) that indicate `c1 cti` was successful are not reset during `c1 pwr 0`.

This is a low priority because this sequence does not occur while a Wombat is in the field.

```
11:32:23.045 > $ c1 pwr 0
11:36:26.452 > AT+CPWROFF
11:36:29.960 >
11:36:29.961 > OK
11:36:29.961 > [2384900][I][CAT_M1.cpp:27] power_supply(): [CAT_M1] state = 0
11:36:29.969 >
11:36:29.969 > OK
11:36:29.969 > $ c1 cti
11:36:35.217 > [2390156][I][CAT_M1.cpp:86] make_ready(): [CAT_M1] already_called = true, early return
11:36:35.222 > AT+CEREG?
11:36:36.237 > AT&K0
11:36:37.258 > AT+UMNOPROF?
11:36:38.280 > [2393219][E][Utils.cpp:397] connect_to_internet(): [utils] Error setting network operator profile
11:36:38.295 >
11:36:38.296 > ERROR
11:36:38.296 > $
```