Fix reference count issue in pyref module function

Author: Wentzell

c++/cpp2py/pyref.hpp

@@ -101,7 +101,8 @@ namespace cpp2py {
     /// Import the module and returns a pyref to it
     static pyref module(std::string const &module_name) {
       // Maybe the module was already imported?
-      PyObject *mod = PyImport_GetModule(PyUnicode_FromString(module_name.c_str()));
+      pyref mod_name = PyUnicode_FromString(module_name.c_str());
+      PyObject *mod  = PyImport_GetModule(mod_name);
 
       // If not, import normally
       if (mod == nullptr) mod = PyImport_ImportModule(module_name.c_str());