patch 7.4.1644

Problem:    Using string() on a partial that exists in the dictionary it binds
            results in an error. (Nikolai Pavlov)
Solution:   Make string() not fail on a recursively nested structure. (Ken
            Takta)

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1644,
 /**/
     1643,
 /**/