Change example of Specialized Feature to multipath, fixes #363

[theri]

Changed example of a Specialized Feature (non-minset) from "encryption" to "automatic handover or failover", as suggested by Anna in #363.
If anyone has an alternative suggestion how to word this, I'm open.

Ideas for alternative solutions include:

• Go back to the "encryption" example, but do not make "encryption" sound like a generic feature but rather talk about specific security protocols, e.g.: "For example, if an application requires encryption of its transport data, it could select a specific security protocol. In this case, only protocol stacks that include this security protocol are eligible to be used."
• Find a different example
• Give up and throw out the example entirely, maybe even changing what a "specialized feature" is

Looking for guidance from the authors here :)