Send correct “support” array in connectWithSession

Sending nil is nonconformant and should result in a disconnection, because
the client is then saying “I don’t support any protocol versions at all”,
according to https://github.com/meteor/meteor/issues/2125 .

Sending “support: [‘pre1’]” is a more correct fix than sending “version: pre2”,
since ObjectiveDDP doesn’t actually support pre2 yet. This is a more correct fix
to https://github.com/boundsj/ObjectiveDDP/issues/74 .