FormatAddress shouldn't insert empty quoted name

[mackstann]

When calling FormatAddress with an empty name, like:

FormatAddress("foo@bar.com", "")

It returns:

"" <foo@bar.com>

But it would be better to return:

<foo@bar.com>

Normally it wouldn't matter all that much, but there is a bug in Go 1.5 and up that rejects such addresses with an error: golang/go#14866

Removing the redundant "" would greatly help work around this Go bug.

In the meantime, a hack like this will work around it:

if name == "" {
    message.SetHeader("To", address) // bypass FormatAddress altogether
} else {
    message.SetAddressHeader("To", address, name)
}

[alexcesaro]

Fixed, thanks!

[mackstann]

Your fast action was very helpful to our team! Thank you!

[alexcesaro]

Glad it helped 😄