Oddly I had exactly the same problem. I left it alone for 6 months, 'cos I couldn't be ar5ed to fix it, and now it's gone away. Maybe the bulbs have blown
You'll know if it doesn't come on when you turn the key.
Personally, i'd get any airbag problem fixed asap. They aren't funny when they deploy, but you will want it to when the time comes. Take it to a reputable garage (preferably a main dealer - they know what they're talking about and have all the ness. kit)
check the connections under the drivers seat,common fault on clios,i have had 3 clios and two of these had a fault with the air bag light,it is the pretensioner.
If it's got passenger airbags too there is a sensor under the passenger seat to sense if there is anyone in it (ie whether the airbag needs firing on the passenger side or not)