relocate the sip directives to fix earlier premature commit

src/wxpy_api.sip

@@ -552,14 +552,6 @@ void i_wxPyReinitializeModules() {
 // Route the various usages of the PyDate_ APIs through our API, so we only
 // have to worry about PyDateTime_IMPORT being needed in one compilation unit.
 
-%ModuleHeaderCode
-    #include <datetime.h>
-%End
-
-%InitialisationCode
-    PyDateTime_IMPORT;
-%End
-
 int i_wxPyDateTime_Check(PyObject *obj) {
     return PyDateTime_Check(obj);
 }
@@ -614,6 +606,15 @@ static wxPyAPI  API = {
 %End
 
 
+%ModuleHeaderCode
+    #include <datetime.h>
+%End
+
+%InitialisationCode
+    PyDateTime_IMPORT;
+%End
+
+
 
 %PostInitialisationCode
     // Code that will run when _core is imported that will stash away a