Add back readResolve() that I removed in r28147 (branch r27997)..

in the other removed cases readResolve was redundant with the XStream Converter,
but in this case it is needed when deserializing a Result sent from a slave node
(XStream is not used in remoting).


git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@28157 71c3de6d-444a-0410-be80-ed276b4c234a