[gimp/gtk3-port: 271/440] themes: uncomment one more deprecated CSS rule.

[Michael Natterer <mitch src gnome org>]

commit 49d0fb88d58a329a024220c5d45b63d905b5e15b
Author: Jehan <jehan girinstud io>
Date:   Tue May 1 05:10:42 2018 +0200

    themes: uncomment one more deprecated CSS rule.
    
    "GtkButton-inner-border" is deprecated and output warnings.

 themes/System/gimp.css |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/themes/System/gimp.css b/themes/System/gimp.css
index a71c19a..f7b7b87 100644
--- a/themes/System/gimp.css
+++ b/themes/System/gimp.css
@@ -83,7 +83,7 @@ GimpDisplayShell {
     -GimpUnitComboBox-label-scale:  0.8333;
     -GimpScaleComboBox-label-scale: 0.8333;
     -GtkComboBox-arrow-size:        8;
-    -GtkButton-inner-border:        0 0 0 0;
+/*    -GtkButton-inner-border:        0 0 0 0; */
 /*    -GtkWidget-focus-line_width:    0; */
 /*    -GtkWidget-focus-padding:       0; */
 }