Fix issue where parse_phrase would return an empty string.
Fix issue where parse_phrase would return an empty string.

It should return None if it failed to find a phrase, like in
"<foo@bar.com>" - as < is not an " or a atext.
Previously it would return an empty string.

buster/rust-email,niax/rust-email,hoodie/rust-email,niax/rust-email,buster/rust-email,hoodie/rust-email,untitaker/rust-email