Abbreviations can be numeric in state province table, avoid using is_numeric / constrain the range

Countries like thailand have numeric abbreviation. however all abbreviations are less than 1000. so we can do a crude hack of:

if is_numeric( $state_province_id ) && (int ) $state_province_id >= 1000

to get around this. Its a bit ugly, but will work in a large number of cases where we die with a fatal message