fixed threadstate swap

plugins/python/python_plugin.c

@@ -859,8 +859,10 @@ void uwsgi_python_enable_threads() {
 	up.gil_get = gil_real_get;
 	up.gil_release = gil_real_release;
 
-	up.swap_ts = threaded_swap_ts;
-	up.reset_ts = threaded_reset_ts;
+	if (uwsgi.threads > 1) {
+		up.swap_ts = threaded_swap_ts;
+		up.reset_ts = threaded_reset_ts;
+	}
 	uwsgi_log("threads support enabled\n");
 
 }

plugins/python/pyutils.c

@@ -12,8 +12,12 @@ PyObject *python_call(PyObject *callable, PyObject *args, int catch) {
 
 	PyObject *pyret;
 
+	uwsgi_log("ready to call %p %p\n", callable, args);
+
 	pyret =  PyEval_CallObject(callable, args);
 
+	uwsgi_log("called\n");
+
 	if (PyErr_Occurred()) {
 		if (PyErr_ExceptionMatches(PyExc_MemoryError)) {
 			uwsgi_log("Memory Error detected !!!\n");

plugins/python/uwsgi_pymodule.c

@@ -436,8 +436,7 @@ PyObject *py_uwsgi_register_rpc(PyObject * self, PyObject * args) {
 
 
 	if (uwsgi_register_rpc(name, 0, argc, func)) {
-		Py_INCREF(Py_None);
-		return Py_None;
+		return PyErr_Format(PyExc_ValueError, "unable to register rpc function");
 	}
 
 	Py_INCREF(Py_True);