rpctest: disable on (bogus) test case

This test would call the service with a bad version number and expect
an UNKNOWNPROTO error. However, this is not how the current tirpc
implementation is supposed to work.

Signed-off-by: Olaf Kirch <okir@suse.de>
Add a test case: make sure rpcinfo -b does not segfault when encountering an interface w/o ifaddr

Signed-off-by: Olaf Kirch <okir@suse.de>