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)
diff --git a/src/version.c b/src/version.c
index c79020b..026b829 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    378,
+/**/
     377,
 /**/
     376,