fix(ios): fix min/max date crash#1008

foyarash wants to merge 2 commits intoreact-native-datetimepicker:masterreact-native-datetimepicker/datetimepicker:masterfrom

foyarash:fix/ios-crash-min-max-datefoyarash/datetimepicker:fix/ios-crash-min-max-dateCopy head branch name to clipboard