Fixes two minor issues in cfg_vanilla (fixes issue #580) (#581)

* fixes two issues with cfg_vanilla: * making iterk and iter0 solver options not point to the same dict. * making the _hasit() function return false if an option is present in the config dict but set to 'False'

* fixing ruff linting issue

---------

Co-authored-by: Tomas <valenciazulu1@llnl.gov>

Author: tvalenciaz

mpisppy/utils/cfg_vanilla.py

@@ -19,7 +19,8 @@
 
 def _hasit(cfg, argname):
     # aside: Config objects act like a dict or an object TBD: so why the and?
-    return cfg.get(argname) is not None and cfg[argname] is not None
+    return cfg.get(argname) is not None and cfg[argname] is not None and \
+        cfg[argname]
 
 def shared_options(cfg):
     shoptions = {
@@ -43,7 +44,7 @@ def shared_options(cfg):
     if _hasit(cfg, "solver_options"):
         odict = sputils.option_string_to_dict(cfg.solver_options)
         shoptions["iter0_solver_options"] = odict
-        shoptions["iterk_solver_options"] = odict
+        shoptions["iterk_solver_options"] = copy.deepcopy(odict)
     # note that specific options usch as mipgap will override        
     if _hasit(cfg, "max_solver_threads"):
         shoptions["iter0_solver_options"]["threads"] = cfg.max_solver_threads