[goffice] GORotationSel: fix pre gtk+ 3.20 ticks.

[Morten Welinder <mortenw src gnome org>]

commit 649c8eb7bdc12c4fec52e8ca83becbf04aceeba1
Author: Morten Welinder <terra gnome org>
Date:   Sun Dec 10 18:41:28 2017 -0500

    GORotationSel: fix pre gtk+ 3.20 ticks.

 goffice/gtk/go-rotation-sel.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/goffice/gtk/go-rotation-sel.c b/goffice/gtk/go-rotation-sel.c
index f9568bf..6b0db34 100644
--- a/goffice/gtk/go-rotation-sel.c
+++ b/goffice/gtk/go-rotation-sel.c
@@ -85,6 +85,8 @@ grs_reload_style (GORotationSel *grs)
 #else
        grs->tick_colour[FALSE] = GO_COLOR_BLACK;
        grs->tick_colour[TRUE] = GO_COLOR_GREEN;
+       grs->tick_outline_colour[FALSE] = GO_COLOR_BLACK;
+       grs->tick_outline_colour[TRUE] = GO_COLOR_BLACK;
 #endif
 }