Warn about overwriting previously imported SMS

[retroconv] / sms.csv~

sms,deliver,"022904719","","","2010.01.15 16:25","","كلمنى شكرا Pls Call Me اتكلم دولي ب1.99جنيه بس للدقيقة.كلم800مجانا"
sms,deliver,"0118010337","","","2010.01.15 16:15","","كلمنى شكرا Pls Call Me اتكلم دولي ب1.99جنيه بس للدقيقة.كلم800مجانا"
sms,deliver,"+20102412751","","","2010.01.14 13:32","","كلمنى شكرا Pls Call Me اتكلم دولي ب1.99جنيه بس للدقيقة.كلم800مجانا"
sms,deliver,"Bianco","","","2010.01.14 11:55","","Leading fashion footwear Brand in Scandinavia, now open in Mohandeseen 15 Jazeerat el Arab, Benefit from our 30% Discount by showing this sms in the shop To stop SMS adds send STOP to 2020 for free"