fix ISR cba setting

[thisconnected]

CBA setting was "Enabled, disabled, uavonly" set as a string instead of number

This fixes an issue where if one of the early checks falls through (switching seats or exiting and entering UAV while in a car) it will crash and thus be unable to use ISR until you exit vehicle

14:10:08 Error in expression <ue, false, (unitIsUAV _currentVehicle)] select arc_isr_enableISR) exitWith {};

>
14:10:08   Error position: <select arc_isr_enableISR) exitWith {};

>
14:10:08   Error select: Type String, expected Number,Bool,Array,code
14:10:08 File /z/arc/addons/isr/functions/fnc_isISR.sqf..., line 9

this is how it should correctly look: