[JENKINS-57244] FilePath (de)serialization via XStream is unsupported but should not be fatal (#4011)
[JENKINS-57244] FilePath (de)serialization via XStream is unsupported but should not be fatal (#4011)

* [JENKINS-57244] FilePath (de)serialization via XStream is unsupported but should not be fatal.

* Factoring out a _getChannelForSerialization with a friendlier message and a redirect.

v1v/jenkins,oleg-nenashev/jenkins,Jochen-A-Fuerbacher/jenkins,v1v/jenkins,Vlatombe/jenkins,oleg-nenashev/jenkins,damianszczepanik/jenkins,daniel-beck/jenkins,DanielWeber/jenkins,rsandell/jenkins,damianszczepanik/jenkins,Vlatombe/jenkins,bkmeneguello/jenkins,patbos/jenkins,rsandell/jenkins,patbos/jenkins,pjanouse/jenkins,Vlatombe/jenkins,jenkinsci/jenkins,v1v/jenkins,rsandell/jenkins,Vlatombe/jenkins,ikedam/jenkins,pjanouse/jenkins,DanielWeber/jenkins,MarkEWaite/jenkins,DanielWeber/jenkins,daniel-beck/jenkins,v1v/jenkins,ikedam/jenkins,damianszczepanik/jenkins,pjanouse/jenkins,damianszczepanik/jenkins,stephenc/jenkins,patbos/jenkins,viqueen/jenkins,DanielWeber/jenkins,recena/jenkins,godfath3r/jenkins,oleg-nenashev/jenkins,Vlatombe/jenkins,damianszczepanik/jenkins,v1v/jenkins,Jochen-A-Fuerbacher/jenkins,recena/jenkins,daniel-beck/jenkins,bkmeneguello/jenkins,ikedam/jenkins,jenkinsci/jenkins,Jochen-A-Fuerbacher/jenkins,viqueen/jenkins,stephenc/jenkins,rsandell/jenkins,jenkinsci/jenkins,oleg-nenashev/jenkins,Vlatombe/jenkins,oleg-nenashev/jenkins,godfath3r/jenkins,ikedam/jenkins,MarkEWaite/jenkins,oleg-nenashev/jenkins,ikedam/jenkins,pjanouse/jenkins,Jochen-A-Fuerbacher/jenkins,jenkinsci/jenkins,stephenc/jenkins,Jochen-A-Fuerbacher/jenkins,MarkEWaite/jenkins,ikedam/jenkins,bkmeneguello/jenkins,Jochen-A-Fuerbacher/jenkins,ikedam/jenkins,viqueen/jenkins,rsandell/jenkins,daniel-beck/jenkins,MarkEWaite/jenkins,DanielWeber/jenkins,godfath3r/jenkins,oleg-nenashev/jenkins,patbos/jenkins,bkmeneguello/jenkins,godfath3r/jenkins,pjanouse/jenkins,jenkinsci/jenkins,stephenc/jenkins,v1v/jenkins,ikedam/jenkins,v1v/jenkins,godfath3r/jenkins,Jochen-A-Fuerbacher/jenkins,MarkEWaite/jenkins,bkmeneguello/jenkins,MarkEWaite/jenkins,daniel-beck/jenkins,viqueen/jenkins,patbos/jenkins,pjanouse/jenkins,patbos/jenkins,daniel-beck/jenkins,rsandell/jenkins,bkmeneguello/jenkins,recena/jenkins,DanielWeber/jenkins,viqueen/jenkins,pjanouse/jenkins,viqueen/jenkins,DanielWeber/jenkins,damianszczepanik/jenkins,stephenc/jenkins,recena/jenkins,MarkEWaite/jenkins,recena/jenkins,patbos/jenkins,stephenc/jenkins,damianszczepanik/jenkins,daniel-beck/jenkins,daniel-beck/jenkins,stephenc/jenkins,recena/jenkins,damianszczepanik/jenkins,recena/jenkins,godfath3r/jenkins,godfath3r/jenkins,rsandell/jenkins,jenkinsci/jenkins,viqueen/jenkins,rsandell/jenkins,bkmeneguello/jenkins,MarkEWaite/jenkins,jenkinsci/jenkins,jenkinsci/jenkins,Vlatombe/jenkins