data/ui/patch-dialog.ui: Remove old property

Author: kaiw

data/ui/patch-dialog.ui

@@ -9,7 +9,6 @@
     <property name="type_hint">dialog</property>
     <property name="skip_taskbar_hint">True</property>
     <property name="skip_pager_hint">True</property>
-    <property name="has_separator">False</property>
     <child internal-child="vbox">
       <object class="GtkVBox" id="dialog-vbox3">
         <property name="visible">True</property>