align to the top

Change-Id: Ib850c509d9d3fdcbe7f16c26804db9337ab77348
Reviewed-on: https://gerrit.libreoffice.org/60532
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

cui/uiconfig/ui/textflowpage.ui

@@ -41,6 +41,9 @@
   <object class="GtkGrid" id="TextFlowPage">
     <property name="visible">True</property>
     <property name="can_focus">False</property>
+    <property name="valign">start</property>
+    <property name="hexpand">True</property>
+    <property name="vexpand">True</property>
     <property name="border_width">6</property>
     <property name="row_spacing">12</property>
     <child>