patch 8.0.0853: crash when running terminal with unknown command

Problem:    Crash when running terminal with unknown command.
Solution:   Check "term" not to be NULL. (Yasuhiro Matsumoto, closes #1932)
diff --git a/src/version.c b/src/version.c
index a029dd5..6170425 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    853,
+/**/
     852,
 /**/
     851,