SRC 116215: [eCost] Unsubscribe: '+' sign removed on email address if unsubscribing to subscription

Problem: User has email address with "+" sign and whenever the user clicks the "Unsubscribe" button in newsletter section of My Accounts page, the "+" sign gets replaced with " ". The email address is used to build a link, so it looks like the http server interpreted the "+" sign as an equivalent of " ".

Solution: Encode email address before using it to build an anchor element in production helper