Resolves: tdf#118520 insert sheet list not horizontally expanded

Change-Id: I0004602631fb82ed13d925a1911ea4ada544462d
Reviewed-on: https://gerrit.libreoffice.org/57632
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sc/uiconfig/scalc/ui/insertsheet.ui

@@ -363,6 +363,7 @@
                                           <object class="GtkTreeView" id="tables">
                                             <property name="visible">True</property>
                                             <property name="can_focus">True</property>
+                                            <property name="hexpand">True</property>
                                             <property name="vexpand">True</property>
                                             <property name="model">liststore1</property>
                                             <property name="headers_visible">False</property>