patch 7.4.1638

Problem:    When binding a function to a dict the reference count is wrong.
Solution:   Decrement dict reference count, only reference the function when
            actually making a copy. (Ken Takata)

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1638,
 /**/
     1637,
 /**/