patch 8.1.2149: crash when running out of memory very early

Problem:    Crash when running out of memory very early.
Solution:   Do not use IObuff when it's NULL. (closes #5052)
diff --git a/src/version.c b/src/version.c
index cf6c773..3fc889e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2149,
+/**/
     2148,
 /**/
     2147,