Enable for selection of multiple objects in Base Geometry list

src/Mod/Path/Gui/Resources/panels/PageBaseGeometryEdit.ui

@@ -70,6 +70,9 @@
        <property name="toolTip">
         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Select one or more features in the 3d view and press 'Add' to add them as the base items for this operation.&lt;/p&gt;&lt;p&gt;&lt;br/&gt;&lt;/p&gt;&lt;p&gt;Selected features can be deleted entirely.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
        </property>
+       <property name="selectionMode">
+        <enum>QAbstractItemView::ExtendedSelection</enum>
+       </property>
       </widget>
      </item>
      <item row="2" column="2">