Simplify the calculation of `PhoneNumber` hash value.
Simplify the calculation of `PhoneNumber` hash value.

Jean-Daniel/PhoneNumberKit,Jean-Daniel/PhoneNumberKit,marmelroy/PhoneNumberKit,Jean-Daniel/PhoneNumberKit,nextforce/PhoneNumberKit,marmelroy/PhoneNumberKit,marmelroy/PhoneNumberKit,marmelroy/PhoneNumberKit,nextforce/PhoneNumberKit,nextforce/PhoneNumberKit