ecore-x xlib errors now only print when sync is enabled

I give up. people continually complain about these and submit them as crashes, so now they're only visible if you set ECORE_X_SYNC. the next step is an #ifdef ISCOMFITOR.

src/lib/ecore_x/xlib/ecore_x_error.c

@@ -99,6 +99,7 @@ static int
 _ecore_x_error_handle(Display *d,
                       XErrorEvent *ev)
 {
+   if (!_ecore_xlib_sync) goto skip;
    switch (ev->error_code)
      {
       case BadRequest:	/* bad request code */
@@ -153,6 +154,7 @@ _ecore_x_error_handle(Display *d,
         ERR("BadImplementation");
         break;
      }
+skip:
    if (d == _ecore_x_disp)
      {
         _error_request_code = ev->request_code;