[fix] Regional.py: (#88) fixes local to intl mobile_no handling

[PavanKumarPacharla]

Pull Request: Fix Automatic '+' Prefix in Mobile Number Handling for WhatsApp Integration

This pull request addresses an issue in the WhatsApp integration for ERPNext using Twilio, where the mobile number handling logic automatically prepends a '+' to all mobile numbers. This behavior caused inconsistencies when processing local and international mobile numbers. The fix ensures that the '+' prefix is only added when necessary, based on the number format and country code, improving reliability for both local and international numbers.

Changes Made

• Modified the mobile number parsing logic to check for existing '+' prefixes before adding one.
• Added validation to handle local numbers without automatically prepending '+' unless required for international formatting.
• Ensured compatibility with Twilio's expected number format for WhatsApp messaging.
  • Add '+' only if it's not already present.
  • Ensure the final format adheres to Twilio's international number standards.

Why This is Needed

Twilio expects phone numbers in the correct E.164 format. Adding an extra '+' led to message delivery failures. This fix ensures numbers are properly formatted before being passed to Twilio.

Testing

• Verified with both local and international number formats.
• Ensured messages were successfully delivered via Twilio after the fix.

Related Issues

Closes: