[geary] Fix two runtime warnings caused by commit 3ef1ac.

[Michael Gratton <mjog src gnome org>]

commit 2e5fe9ea86ef44e168dc026cca868ed5414d45d0
Author: Michael James Gratton <mike vee net>
Date:   Thu Dec 8 18:59:42 2016 +1100

    Fix two runtime warnings caused by commit 3ef1ac.

 .../conversation-viewer/conversation-viewer.vala   |   28 +++++++++----------
 1 files changed, 13 insertions(+), 15 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-viewer.vala 
b/src/client/conversation-viewer/conversation-viewer.vala
index 55b52a4..4366e3f 100644
--- a/src/client/conversation-viewer/conversation-viewer.vala
+++ b/src/client/conversation-viewer/conversation-viewer.vala
@@ -326,21 +326,19 @@ public class ConversationViewer : Gtk.Stack {
         }
     }
 
-    // XXX We can't use this signal with GTK 3.14.
-    // [GtkCallback]
-    // private void on_find_next(Gtk.Widget entry) {
-    //     if (this.current_list != null) {
-    //         //this.current_list.show_prev_search_term();
-    //     }
-    // }
-
-    // XXX We can't use this signal with GTK 3.14.
-    // [GtkCallback]
-    // private void on_find_prev(Gtk.Widget entry) {
-    //     if (this.current_list != null) {
-    //         //this.current_list.show_next_search_term();
-    //     }
-    // }
+    [GtkCallback]
+    private void on_find_next(Gtk.Widget entry) {
+         if (this.current_list != null) {
+             //this.current_list.show_prev_search_term();
+         }
+    }
+
+    [GtkCallback]
+    private void on_find_prev(Gtk.Widget entry) {
+        if (this.current_list != null) {
+            //this.current_list.show_next_search_term();
+        }
+    }
 
 }