patch 8.0.0264: memory error reported by ubsan

Problem:    Memory error reported by ubsan, probably for using the string
            returned by execute().
Solution:   NUL terminate the result of execute().

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    264,
 /**/
     263,
 /**/