[gitg/wip/ricotz/vala] libgitg: Fix mismatch of type-parameter ownership

[Rico Tzschichholz <ricotz src gnome org>]

commit 6a0571fc47daa220f28838d7a28a14da4f3de7e2
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Nov 4 15:13:49 2018 +0100

    libgitg: Fix mismatch of type-parameter ownership

 libgitg/gitg-lanes.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/libgitg/gitg-lanes.vala b/libgitg/gitg-lanes.vala
index 780fa092..1af72e05 100644
--- a/libgitg/gitg-lanes.vala
+++ b/libgitg/gitg-lanes.vala
@@ -469,7 +469,7 @@ public class Lanes : Object
                index = next;
                uint cnt = 0;
 
-               unowned SList<Commit> ptr = d_previous;
+               unowned SList<weak Commit> ptr = d_previous;
 
                while (ptr != null)
                {