Fix limitations which do not allow to send email with multiple bcc
Fix limitations which do not allow to send email with multiple bcc

This request would help you to fix a nasty bug - limitations which do not allow to send email with multiple bcc.
When we add multiple bcc, we get a multidimensional array and an error :

 [php] Array to string conversion

in:

vendor/sendgrid/sendgrid/lib/SendGrid.php:51
lucasmezencio/sendgrid-php,sendgrid/sendgrid-php,taz77/sendgrid-php,admiraalmichiel/sendgrid-php,tonyle/sendgrid-php,ninsuo/sendgrid-php,karlpitcher/MeterReadings,tonyle/sendgrid-php,steptan/sendgrid-php,steptan/sendgrid-php,sendgrid/sendgrid-php,karlpitcher/MeterReadings,lucasmezencio/sendgrid-php,matthiaz/sendgrid-php,matthiaz/sendgrid-php,taz77/sendgrid-php,ninsuo/sendgrid-php,admiraalmichiel/sendgrid-php