[shotwell] Remove deprecated function in histogram

[Jens Georg <jensgeorg src gnome org>]

commit f286c01022f4180122eff7c64df366d7302137fb
Author: Jens Georg <mail jensge org>
Date:   Mon Apr 10 20:37:16 2017 +0200

    Remove deprecated function in histogram
    
    Signed-off-by: Jens Georg <mail jensge org>

 src/editing_tools/RGBHistogramManipulator.vala |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/src/editing_tools/RGBHistogramManipulator.vala b/src/editing_tools/RGBHistogramManipulator.vala
index 2379533..381907c 100644
--- a/src/editing_tools/RGBHistogramManipulator.vala
+++ b/src/editing_tools/RGBHistogramManipulator.vala
@@ -196,7 +196,6 @@ public class RGBHistogramManipulator : Gtk.DrawingArea {
     
     private void force_update() {
         get_window().invalidate_rect(null, true);
-        get_window().process_updates(true);
     }
     
     private void update_nub_extrema() {