The “onlyclearglobals” option was not actually clearing global variables

The driver was calling “clear” before “global”, hence clearing local and not
global variables (unless “global” had already been called at scope).

Rather use “clearvars -global”.

src/ModFile.cc

@@ -1065,8 +1065,8 @@ ModFile::writeMOutput(const string& basename, bool clear_all, bool clear_global,
     mOutputFile << "clearvars -global" << endl
                 << "clear_persistent_variables(fileparts(which('dynare')), false)" << endl;
   else if (clear_global)
-    mOutputFile
-        << "clear M_ options_ oo_ estim_params_ bayestopt_ dataset_ dataset_info estimation_info;"
+    mOutputFile << "clearvars -global M_ options_ oo_ estim_params_ bayestopt_ dataset_ "
+                   "dataset_info estimation_info;"
                 << endl;
 
   if (!notime)