patch 9.0.1477: crash when recovering from corrupted swap file

Problem:    Crash when recovering from corrupted swap file.
Solution:   Check for a valid page count. (closes #12275)
diff --git a/src/version.c b/src/version.c
index 1ffff63..c94a503 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1477,
+/**/
     1476,
 /**/
     1475,