Resolves: tdf#121270 use never scrollbar policy for gtk 3.18

Change-Id: I76df258c822b7811024f3bb6f96bafbc3298b15d
Reviewed-on: https://gerrit.libreoffice.org/63105
Reviewed-by: Xisco Faulí <xiscofauli@libreoffice.org>
Tested-by: Xisco Faulí <xiscofauli@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/cui/uiconfig/ui/fontfeaturesdialog.ui b/cui/uiconfig/ui/fontfeaturesdialog.ui
index b3db983..cb619ea 100644
--- a/cui/uiconfig/ui/fontfeaturesdialog.ui
+++ b/cui/uiconfig/ui/fontfeaturesdialog.ui
@@ -86,6 +86,8 @@
              <object class="GtkScrolledWindow" id="contentWindow">
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="hscrollbar_policy">never</property>
                <property name="vscrollbar_policy">never</property>
                <property name="shadow_type">in</property>
                <child>
                  <object class="GtkViewport">