tdf83825 Vertically center left and right margin labels

Change-Id: I583fc112333df6af3898b03f632780538b5f046f
Reviewed-on: https://gerrit.libreoffice.org/19469Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit f5cf8524)
Reviewed-on: https://gerrit.libreoffice.org/19572Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
(cherry picked from commit ce260308)

cui/uiconfig/ui/pageformatpage.ui

@@ -434,6 +434,7 @@
                         <property name="visible">True</property>
                         <property name="can_focus">False</property>
                         <property name="orientation">vertical</property>
+                        <property name="valign">center</property>
                         <child>
                           <object class="GtkLabel" id="labelRightMargin">
                             <property name="can_focus">False</property>
@@ -475,6 +476,7 @@
                         <property name="visible">True</property>
                         <property name="can_focus">False</property>
                         <property name="orientation">vertical</property>
+                        <property name="valign">center</property>
                         <child>
                           <object class="GtkLabel" id="labelLeftMargin">
                             <property name="can_focus">False</property>