Catch keypress event in discovery window

data/gui/service_discovery_window.ui

@@ -97,6 +97,7 @@ Agent JID - node</property>
                   <object class="GtkEntry" id="address_entry">
                     <property name="can_focus">True</property>
                     <property name="has_focus">True</property>
+                    <signal name="key-press-event" handler="_on_entry_key_press_event" swapped="no"/>
                   </object>
                 </child>
               </object>

src/disco.py

@@ -857,6 +857,10 @@ _('Without a connection, you can not browse available services'))
         if self.browser:
             self.browser.update_actions()
 
+    def _on_entry_key_press_event(self, widget, event):
+        if event.keyval == Gdk.KEY_Return or event.keyval == Gdk.KEY_KP_Enter:
+            self.on_go_button_clicked(widget)
+
 
 class AgentBrowser:
     """