fix(get value): fixed error handling when modflowapi fails to get a pointer to a value from the API (#9)

Co-authored-by: scottrp <45947939+scottrp@users.noreply.github.com>

Author: spaulins-usgs

modflowapi/extensions/data.py

@@ -558,7 +558,7 @@ def get_variable(self, name, model=None, package=None):
 
         try:
             values = self.mf6.get_value_ptr(var_addr)
-        except InputError:
+        except xmipy.errors.InputError:
             values = self.mf6.get_value(var_addr)
 
         self._ptrs[name.lower()] = values