[TIMOB-10889] iOS: setting remoteBackup to false leads to memory leaks

Problem description

Setting a database file so that it is not backed up remotely leads to memory leaks in the app.

Steps to reproduce

- Create an app.js with the following code:

(function() {
var db = Ti.Database.open("somedb");
db.file.remoteBackup = false; // comment this line and leaks disappears
db.close();
db = null;
}());

- Run the app using XCode profiling, and open the Instruments tool to check leaks - Wait ~1 minute and the following leaks are shown:

TiFilesystemFileProxy
NSFileManager
NSPathStore2

- Comment the remoteBackup line and leaks won't show up.