updated for version 7.4.556

Problem:    Failed commands in Python interface not handled correctly.
Solution:   Restore window and buffer on failure.

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    556,
 /**/
     555,
 /**/