correcting bug introduced by recursive code, when there is no recursive estimation

git-svn-id: https://www.dynare.org/svn/dynare/trunk@2376 ac1d8469-bf42-47a9-8791-bf33cf982152

matlab/dynare_estimation.m

@@ -33,7 +33,12 @@ global options_ oo_ M_ oo_recursive_
 var_list = check_list_of_variables(options_, M_, var_list);
 options_.varlist = var_list;
 
-nobs = options_.nobs;
+if isfield(options_,'nobs')
+    nobs = options_.nobs;
+else
+    nobs = [];
+end
+
 nnobs = length(nobs);
 horizon = options_.forecast;