remove obsolete differences since TLS 1.1 section

TLS 1.1 [RFC 4346] & TLS 1.2 [RFC 5246] each only have a list of changes from the immediately previous version. This current draft has both the current changelog since TLS 1.2 and the old list of changes from TLS 1.1 to 1.2. The contents of this old section are no longer relevant, in particular it mentions TLS_RSA_WITH_AES_128_CBC_SHA as MTI which is no longer permitted at all. Suggesting just removing this now.