Fixed obsoleted RFCs in reference

RFC 1305 (Obsoleted by RFC 5905)
RFC 2373 (Obsoleted by RFC 3513)
RFC 2401 (Obsoleted by RFC 4301)
RFC 2434 (Obsoleted by RFC 5226)
RFC 2461 (Obsoleted by RFC 4861)
RFC 2462 (Obsoleted by RFC 4862)
RFC 3041 (Obsoleted by RFC 4941)