v4 tests/arima/mod1c.mod: use new syntax for unit_root_vars

git-svn-id: https://www.dynare.org/svn/dynare/dynare_v4@1868 ac1d8469-bf42-47a9-8791-bf33cf982152

tests/arima/mod1c.mod

@@ -23,5 +23,5 @@ stderr y,INV_GAMMA_PDF,0.01,inf;
 end;
 
 varobs x y;
-options_.unit_root_vars = {'x'; 'y'};
+unit_root_vars x y;
 estimation(datafile=data1,nobs=1000,mh_replic=2000,lik_init=2);
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