vcview.ui: Don't map the commit dialog before we've set a parent

Author: kaiw

data/ui/vcview.ui

@@ -130,7 +130,7 @@
     </child>
   </object>
   <object class="GtkDialog" id="commitdialog">
-    <property name="visible">True</property>
+    <property name="visible">False</property>
     <property name="can_focus">False</property>
     <property name="border_width">12</property>
     <property name="title" translatable="yes">Commit</property>