[seahorse] Ssh: add the length of ED25519 keys.

[Niels De Graef <nielsdg src gnome org>]

commit f70aad8f96c7112a2659f528b3d0f685e3f64607
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Wed Mar 7 18:36:03 2018 +0100

    Ssh: add the length of ED25519 keys.

 ssh/key-data.vala |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/ssh/key-data.vala b/ssh/key-data.vala
index 4c2c496..3e35ba0 100644
--- a/ssh/key-data.vala
+++ b/ssh/key-data.vala
@@ -130,6 +130,9 @@ public class Seahorse.Ssh.KeyData : GLib.Object {
                 uint n = ((len - 50) * 8) / 3;
                 return ((n / 64) + (((n % 64) > 32) ? 1 : 0)) * 64; // round to 64
 
+            case Algorithm.ED25519:
+                return 256;
+
             default:
                 return 0;
         }