Fix cause of HTTP 406 responses
Fix cause of HTTP 406 responses

blackpioter/sendgrid-python,galihmelon/sendgrid-python,gabrielkrell/sendgrid-python,gabrielkrell/sendgrid-python,galihmelon/sendgrid-python,sendgrid/sendgrid-python,gabrielkrell/sendgrid-python,galihmelon/sendgrid-python,sendgrid/sendgrid-python,blackpioter/sendgrid-python,sendgrid/sendgrid-python,blackpioter/sendgrid-python