rep suppr_contact(rep reper,char nom[])
{
    int i = 0;
        while (i<reper.rang && strcmp(nom,reper.tab[i].nom)!=0)
        {
           i++;
        }
    for (int j = i; j < i-1; j++)
    {
        reper.tab[i]=reper.tab[i+1];
    }
    return reper;
}