[MOD-2280] Facebook: fb.permissions leading to crash inconsistently on iOS

var win = Ti.UI.createWindow({
	backgroundColor: "white",
});

// facebook
var fb = require('facebook');
fb.initialize();
fb.addEventListener('login', function(e) {
    if (e.success) {
        Ti.API.info('login from uid: '+e.uid+', name: '+ JSON.parse(e.data).name);
        checkPermission();
    }
    else if (e.cancelled) {
        alert('cancelled');
    }
    else {
        alert(e.error);
    }
});

// button to tigger facebook authorise and check the permission
var button = Ti.UI.createButton({
	title:"Authorise and check the permission",
	top: 100
});
button.addEventListener('click',function(e){
	if (!fb.loggedIn) {
		console.log("not logged yet.");
		fb.authorize();
	} else {	
		checkPermission();
	}
});
win.add(button);

function checkPermission() {
	if(fb.permissions.indexOf('publish_actions') < 0) {
		Ti.API.info("No publish_action permission");
	} else {
		Ti.API.info("Do have publish_action permission");
	}
}

win.open();