deploy-stub: Set `Py_OptimizeFlag` to 2 for Python 3.2+

This fixes the value of `sys.flags.optimize`, as we always build Python code with `optimize=2` in Python 3.2 and above

In the long run we need a better solution, see #1363

Closes #1359
Fixes #1343

pandatool/src/deploy-stub/deploy-stub.c

@@ -441,6 +441,10 @@ int Py_FrozenMain(int argc, char **argv)
     Py_NoSiteFlag = 0;
     Py_NoUserSiteDirectory = 1;
 
+#if PY_VERSION_HEX >= 0x03020000
+    Py_OptimizeFlag = 2;
+#endif
+
 #ifndef NDEBUG
     if ((p = Py_GETENV("PYTHONINSPECT")) && *p != '\0')
         inspect = 1;