patch 8.1.0797: error E898 is used twice

Problem:    Error E898 is used twice.
Solution:   Rename the Blob error to E899. (closes #3853)
diff --git a/src/version.c b/src/version.c
index a4decba..e22ebcb 100644
--- a/src/version.c
+++ b/src/version.c
@@ -792,6 +792,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    797,
+/**/
     796,
 /**/
     795,