update README file to depend on python-dbus >=0.81, which is needed for...

update README file to depend on python-dbus >=0.81, which is needed for bus.list_names() function. Fixes #5474

README.html

@@ -38,7 +38,7 @@ Gajim is a GTK+ app that loves GNOME. You can do 'make' so you don't require gno
 <li>gnome-python-desktop (for GnomeKeyring support)</li>
 <li>notification-daemon or notify-python (and D-Bus) to get cooler popups</li>
 <li>D-Bus running to have gajim-remote working. Some distributions split dbus-x11, which is needed for dbus to work with Gajim. Version >= 0.80 is required.</li>
-<li>python-dbus bindings (>=0.80)</li>
+<li>python-dbus bindings (>=0.81)</li>
 <li>python-sexy to have clickable URLs in chat windows</li>
 <li>python-kerberos to use GSSAPI authentification. Note: version1.1 or higher is required</li>
 </ul>