Update metadata for support Pakistan 326 codes

[aikikode]

This library has the same issue as nyaruka/phonenumbers#110: due to outdated metadata Pakistan mobile phone matching pattern is

national_number_pattern:"3(?:[014]\\d|2[0-5]|3[0-7]|55|64)\\d{7}" possible_length:10 example_number:"3012345678"

That only includes codes 320-325, while 326 is also a valid one.

The code:

package main

import (
    "fmt"
    "github.com/ttacon/libphonenumber"
)

func main() {
    parsedPhoneNumber, _ := libphonenumber.Parse("0325-0000000", "PK")
    fmt.Println(parsedPhoneNumber, libphonenumber.IsValidNumber(parsedPhoneNumber))
    parsedPhoneNumber, _ = libphonenumber.Parse("0326-0000000", "PK")
    fmt.Println(parsedPhoneNumber, libphonenumber.IsValidNumber(parsedPhoneNumber))
}

Provides:

country_code:92 national_number:3250000000  true
country_code:92 national_number:3260000000  false // should be true