app_python3: fix threads_mode = 1

- fixes gh #4153
- commit 0ffe157: incorrect use of thread-local storage
    to save python thread state

src/modules/app_python3/app_python3_mod.c

@@ -59,7 +59,7 @@ int _apy_process_rank = 0;
 int _ksr_apy3_threads_mode = 0;
 
 PyThreadState *myThreadState = NULL;
-__thread PyThreadState *_save = NULL;
+PyThreadState *_save = NULL;
 
 /* clang-format off */
 /** module parameters */

src/modules/app_python3/python_exec.c

@@ -49,7 +49,7 @@ sr_apy_env_t *sr_apy_env_get()
 	return &_sr_apy_env;
 }
 
-extern __thread PyThreadState *_save;
+extern PyThreadState *_save;
 extern int _ksr_apy3_threads_mode;
 
 #define LOCK_RELEASE \