change internal API for Message::Metadata::parse_received_line(), return the value instead of pushing onto an array.  also got rid of unnecessary temp arrays.
change internal API for Message::Metadata::parse_received_line(), return the value instead of pushing onto an array.  also got rid of unnecessary temp arrays.

git-svn-id: e9fe9b84e32fc5e57b7d09c40cd78b14ea28ed71@56641 13f79535-47bb-0310-9956-ffa450edef68

apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin,apache/spamassassin