fix: ERROR: Radisk needs store.put interface (#1374)

Author: aheissenberger

Diff for: lib/rfs.js

@@ -83,7 +83,7 @@ Gun.on('create', function(root){
 	this.to.next(root);
 	var opt = root.opt;
 	if(opt.rfs === false){ return }
-	opt.store = opt.store || (!Gun.window || opt.rfs === true && Store(opt));
+	opt.store = opt.store || ((!Gun.window || opt.rfs === true) && Store(opt));
 });
 
 module.exports = Store;