Temporary solution for crashing when using both :py and :py3: disallow both in
one session.
diff --git a/src/proto/if_python.pro b/src/proto/if_python.pro
index 793b6ee..ec12402 100644
--- a/src/proto/if_python.pro
+++ b/src/proto/if_python.pro
@@ -1,6 +1,7 @@
/* if_python.c */
int python_enabled __ARGS((int verbose));
void python_end __ARGS((void));
+int python_loaded __ARGS((void));
void ex_python __ARGS((exarg_T *eap));
void ex_pyfile __ARGS((exarg_T *eap));
void python_buffer_free __ARGS((buf_T *buf));