awesomerc: put systray into statusbar

table.insert doesn't work on statusbar.widgets because statusbar.widgets
always returns a new copy.

'condition and a or b' works like 'condition ? a : b' in C.

Signed-off-by: Julien Danjou <julien@danjou.info>

awesomerc.lua.in

@@ -144,11 +144,11 @@ for s = 1, screen.count() do
         mytasklist,
         mypromptbox,
         mytextbox,
-        mylayoutbox[s]
+        mylayoutbox[s],
+        s == screen.count() and mysystray or nil
     }
     mystatusbar[s].screen = s
 end
-table.insert(mystatusbar[screen.count()].widgets, mysystray)
 -- }}}
 
 -- {{{ Mouse bindings