Update domains.csv with hs-mittweida mail (#336)

hs-mittweida.de,mail.hs-mittweida.de,993,mail.hs-mittweida.de,465

share/domains.csv

@@ -279,3 +279,4 @@ yandex.ua,imap.yandex.com,993,smtp.yandex.com,587
 zoho.com,imap.zoho.com,993,smtp.zoho.com,465
 polito.it,mail.polito.it,993,mail.polito.it,465
 studio.unibo.it,outlook.office365.com,993,smtp.office365.com,587
+hs-mittweida.de,mail.hs-mittweida.de,993,mail.hs-mittweida.de,465