patch 7.4.1581

Problem:    Using ":call dict.func()" where the function is a partial does
            not work.  Using "dict.func()" where the function does not take a
            Dictionary does not work.
Solution:   Handle partial properly in ":call". (Yasuhiro Matsumoto)

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1581,
 /**/
     1580,
 /**/