Fix "similar-code" issue in sendgrid/helpers/mail/personalization.py

[thinkingserious]

Similar blocks of code found in 3 locations. Consider refactoring.

https://codeclimate.com/github/sendgrid/sendgrid-python/sendgrid/helpers/mail/personalization.py#issue_59f639d0343eae000100009f

[defaults]

@thinkingserious hey can you please code review and merge #493. I have fixed codeclimate issues with personalization.py

[thinkingserious]

Since there has been no activity on this issue since March 1, 2020, we are closing this issue. Please feel free to reopen or create a new issue if you still require assistance. Thank you!