Repair more now-obsolete references to config.h.
diff --git a/Include/pymem.h b/Include/pymem.h
index 71fc8b5..86a69e4 100644
--- a/Include/pymem.h
+++ b/Include/pymem.h
@@ -140,7 +140,7 @@
 
    d_malloc(size_t n, char* src_file, unsigned long src_line) c.s.
 
-   In this case, you would define (for example in config.h) :
+   In this case, you would define (for example in pyconfig.h) :
 
    #define PyCore_MALLOC_FUNC      d_malloc
    ...