Fix: detect RPC endpoint and SSH multiplexing conf

better to replace with
```perl
my $res= $oneversion >= MINIMAL_ONE_VERSION;
if ($res) {
   $self->verbose("Version $oneversion is ok.");
} else {
    $self->error("OpenNebula AII requires ONE v".ONEVERSION." or higher (found $oneversion).");
}
return $res;
```