Edit bootstrap servers as a list + GtkQTreeModel API changes

This allows for editing bootstrap servers as a list instead of a text
field.

The GtkQTreeModel API was changed to allow displaying other columns.

Tuleap: #696
Change-Id: I8b6072860c6cd3c01477702cd943ab27af8c39fc
diff --git a/src/utils/models.cpp b/src/utils/models.cpp
index db0a4b3..793abd1 100644
--- a/src/utils/models.cpp
+++ b/src/utils/models.cpp
@@ -155,7 +155,7 @@
         model = (GtkTreeModel *)gtk_q_tree_model_new(
             qmodel,
             1,
-            Qt::DisplayRole, G_TYPE_STRING);
+            0, Qt::DisplayRole, G_TYPE_STRING);
     }
 
     /* use a filter model to remove disabled items */