patch 8.0.0493: crash with cd command with very long argument

Problem:    Crash with cd command with very long argument.
Solution:   Check for running out of space. (Dominique pending, closes #1576)
diff --git a/src/version.c b/src/version.c
index 75afd62..72516f0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    493,
+/**/
     492,
 /**/
     491,