patch 8.0.0378: possible overflow when reading corrupted undo file

Problem:    Another possible overflow when reading corrupted undo file.
Solution:   Check if allocated size is not too big. (King)

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    378,
 /**/
     377,
 /**/