Resolves: tdf#122880 list of obj types at 0 height with gtk 3.18

Change-Id: Ib50bc94d1dd4c90cf1516110d413c480aff603ab
Reviewed-on: https://gerrit.libreoffice.org/66739
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/sw/uiconfig/swriter/ui/optcaptionpage.ui b/sw/uiconfig/swriter/ui/optcaptionpage.ui
index 779503e..d56d14d 100644
--- a/sw/uiconfig/swriter/ui/optcaptionpage.ui
+++ b/sw/uiconfig/swriter/ui/optcaptionpage.ui
@@ -425,6 +425,8 @@
                        <property name="can_focus">True</property>
                        <property name="hexpand">True</property>
                        <property name="vexpand">True</property>
                        <property name="hscrollbar_policy">never</property>
                        <property name="vscrollbar_policy">never</property>
                        <property name="shadow_type">in</property>
                        <child>
                          <object class="GtkTreeView" id="objects">