Fix tty switching for desktop_notifications

Lately, we can't be sure the desktop will be on tty1 after we
do 'systemctl isolate graphical.target'. For recent Workstation
lives it actually shows up on tty2.

We could be 'clever' and switch to tty2 on F29+ Workstation
lives...but actually it seems like if we just don't do anything,
systemd switches us to the correct tty. So let's rely on that,
at least as long as it's working.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

tests/desktop_notifications.pm

@@ -51,7 +51,7 @@ sub run {
         }
     }
     assert_script_run 'systemctl isolate graphical.target';
-    send_key 'ctrl-alt-f1';
+    # we trust systemd to switch us to the right tty here
     if (get_var("BOOTFROM")) {
         assert_screen 'graphical_login';
         wait_still_screen 3;