Set from email incorrect error message

[oleddzo]

Hello, I've found an issue, when I set incorrect email to FROM get an error '$email must be valid and of type string.', but $email in the string should be a value that I try to set. I figured out why it happened, in this function SendGrid\Mail\Mail::setFrom you should replace single-quotes to double-quotes in the error message. Thank you.

[childish-sambino]

Nice find. Working on a fix ...

[kampalex]

Similar to issue #841.
Fixing the $email in the string should be a value that I try to set may be simple, but this only works if an invalid string is provided. Also mentioned during review.

I think a more durable solution is needed like already contributed #762.

[childish-sambino]

@kampalex Good call. Slowly working through old PRs but Octobers get crazy. I'll probably fix up that PR to resolve this issue.