Remove superflous xcb_flush() call (Issue #108)

Some lines down we are calling awesome_refresh(). That function already calls
xcb_flush() for us.

Signed-off-by: Uli Schlachter <psychon@znc.in>

awesome.c

@@ -540,7 +540,6 @@ main(int argc, char **argv)
     scan(tree_c);
 
     luaA_emit_startup();
-    xcb_flush(globalconf.connection);
 
     /* Setup the main context */
     g_main_context_set_poll_func(g_main_context_default(), &a_glib_poll);