patch 8.1.1618: Amiga-like systems quickly run out of stack

Problem:    Amiga-like systems quickly run out of stack.
Solution:   Reserve a Megabyte stack. (Ola Söder, closes #4608)
diff --git a/src/version.c b/src/version.c
index 35575e2..10e4c40 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1618,
+/**/
     1617,
 /**/
     1616,