TypeError: string indices must be integers

## Alarm system
SP600 Panel
IP150 with Insite Gold
v4.42.002 firmware

## Environment
Hassio

## Git branch
I've tested both current dev and production

## Describe the bug
Unable to connect to the IP150. Getting an error which seems to suggest the serial number is in the incorrect format.

## To Reproduce
This is a recently installed alarm, I can reach the web interface on port 80 and enter my code to access the IP150, but with very limited setting (no zone statuses, etc). Insite Gold is active and working. My config (I have replaced sensitive parts):

CONNECTION_TYPE: IP
IP_CONNECTION_HOST: aaa.bbb.ccc.ddd
IP_CONNECTION_PORT: 10000
IP_CONNECTION_PASSWORD: paradox
IP_CONNECTION_SITEID: MYHOUSE
IP_CONNECTION_EMAIL: xxxxx@aaaa.bbb
IP_CONNECTION_PANEL_SERIAL: 1111AA2BB
IP_CONNECTION_BARE: false
PASSWORD: '1111'


## Logs
Attached.
[pai-debug-log-2020-11-15.txt](https://github.com/ParadoxAlarmInterface/pai/files/5543022/pai-debug-log-2020-11-15.txt)
