[Geary] accented letters not displayed correctly

[Federico Bruni <fede inventati org>]

Hi all

I'm using master da2d2c9840f52c4cb9a28af7b227b99db3654630

When I send emails (in plain text) containing accented letters (like à 
è ì ò ù), they are displayed with weird letters either in Geary or 
in Gmail (I guess in any client?).
The message source says:

X-Mailer: geary/0.11.0
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Transfer-Encoding: base64

w6Agw6ggw6wgw7Igw7kNCnRlc3QgbGV0dGVyZSBhY2NlbnRhdGUNCg0KDQo=


My locale is UTF-8:

$ echo $LANG
it_IT.UTF-8


I guess that this is due to this commit:

commit 0c3160779e93ff1716f13a64595baa0233f76e52
Author: Michael James Gratton <...>
Date:   Mon Aug 1 23:21:28 2016 +1000

   Don't always UTF-8 as the charset, use ASCII or 8859-1 if possible.