Remove unimplemented software updater option. Fix potential double start of updater service.

indra/newview/llviewercontrol.cpp

@@ -506,7 +506,8 @@ void toggle_updater_service_active(LLControlVariable* control, const LLSD& new_v
 {
     if(new_value.asInteger())
     {
-        LLUpdaterService().startChecking();
+		LLUpdaterService update_service;
+		if(!update_service.isChecking()) update_service.startChecking();
     }
     else
     {

indra/newview/skins/default/xui/en/panel_preferences_setup.xml

@@ -367,10 +367,12 @@
          label="Install automatically"
          name="Install_automatically"
          value="3" />
+      <!--
         <combo_box.item
          label="Ask before installing"
          name="Install_ask"
          value="1" />
+      -->
         <combo_box.item
          label="Download and install updates manually"
          name="Install_manual"