Menubar: silence find warnings

Signed-off-by: Gregor Best <gbe@ring0.de>
Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/menubar/utils.lua.in

@@ -181,7 +181,7 @@ end
 -- @return A table with all .desktop entries.
 function utils.parse_dir(dir)
     local programs = {}
-    local files = io.popen('find '.. dir ..' -maxdepth 1 -name "*.desktop"')
+    local files = io.popen('find '.. dir ..' -maxdepth 1 -name "*.desktop" 2>/dev/null')
     for file in files:lines() do
         table.insert(programs, utils.parse(file))
     end