Fix setting piggyback for agent

[moschlar]

I noticed that line always ends with \n - so naturally it never equals True - therefore I decided to just always strip the line of such arbitrary whitespace characters, like it is already done for most if the other cases.

[Bastian-Kuhn]

Hello, this one is already known and fixes but not committed since there are more problems with the swarm path, which needs to be addressed first.