Turning off the airbag warning light on a vehicle is unsafe. The light is on for a reason, either a bad sensor, or an issue with the airbag. Either way, you should bring this in to a mechanic to have it looked at.
The circle with 3 broken lines either side is almost universally a symbol for "breaks". If I remember correctly, on a Vectra it's the ABS warning light, and means that the ABS system has failed it's self-diagnostic test, and has turned it self off.