[shotwell] Revert accidental Gtk.Alignment changes

[Jens Georg <jensgeorg src gnome org>]

commit 2b188c92f3863879680bd87dadd4306afe92853e
Author: Jens Georg <mail jensge org>
Date:   Sun Aug 28 23:12:18 2016 +0200

    Revert accidental Gtk.Alignment changes
    
    Signed-off-by: Jens Georg <mail jensge org>

 src/Dialogs.vala |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/src/Dialogs.vala b/src/Dialogs.vala
index 10f2e43..f01e078 100644
--- a/src/Dialogs.vala
+++ b/src/Dialogs.vala
@@ -1766,10 +1766,11 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
         hbox.set_border_width(3);
         hbox.pack_start(image_content, true, false, 0);
         hbox.pack_start(time_content, true, false, 0);
-        hbox.valign = Gtk.Align.CENTER;
-        hbox.halign = Gtk.Align.CENTER;
 
-        ((Gtk.Box) get_content_area()).pack_start(hbox, true, false, 0);
+        Gtk.Alignment hbox_alignment = new Gtk.Alignment(0.5f, 0.5f, 0, 0);
+        hbox_alignment.add(hbox);
+
+        ((Gtk.Box) get_content_area()).pack_start(hbox_alignment, true, false, 0);
 
         notification = new Gtk.Label("");
         notification.set_line_wrap(true);