Update vehicle_thinkcity.c

;    Changes:
;    2.3  02.09.2013 (Haakon)
;         - Bugfix to get GPS streaming (FEATURE 9 = 1) working
;         - Added correct value to car_speed and set car_doors1bits.CarON = 1 when tc_bit_dischgenbl > 0
;           (car has to be moving and 'car on' is detected when discharge is allowed)
;         - Added car_SOCalertlimit = 10 to set a system alert when SOC < 10