[folks] Fix the signature of RoleFieldDetails.equal()

[Travis Reitter <treitter src gnome org>]

commit 8d86791dfb9595a1e220292fc6b20650e1f1d1b1
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Wed Oct 19 14:23:41 2011 -0700

    Fix the signature of RoleFieldDetails.equal()
    
    Helps: bgo#662433 - AbstractFieldDetails.equal() is ambiguous about
    checking parameters.

 folks/role-details.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/folks/role-details.vala b/folks/role-details.vala
index c012502..62cc712 100644
--- a/folks/role-details.vala
+++ b/folks/role-details.vala
@@ -164,7 +164,7 @@ public class Folks.RoleFieldDetails : AbstractFieldDetails<Role>
    *
    * @since 0.6.0 
    */
-  public override bool equal (AbstractFieldDetails<string> that)
+  public override bool equal (AbstractFieldDetails<Role> that)
     {
       var that_fd = that as RoleFieldDetails;