Select correct notebook tab - Fixes #133

plugin_installer/manifest.ini

 [info]
 name: Plugin Installer
 short_name: plugin_installer
-version: 0.14
+version: 0.15
 description: Install and upgrade plugins from ftp
 authors: Denis Fomin <fominde@gmail.com>
  Yann Leboulanger <asterix@lagaule.org>

plugin_installer/plugin_installer.py

@@ -102,7 +102,8 @@ class PluginInstaller(GajimPlugin):
             self.upgrading = True
             self.pl_menuitem.activate()
             nb = gajim.interface.instances['plugins'].plugins_notebook
-            GLib.idle_add(nb.set_current_page, 1)
+            page = nb.page_num(self.hpaned)
+            GLib.idle_add(nb.set_current_page, page)
         if plugins:
             plugins_str = '\n'.join(plugins)
             YesNoDialog(_('Plugins updates'), _('Some updates are available for'