patch 9.0.0948: 'ttyfast' is set for arbitrary terminals

Problem:    'ttyfast' is set for arbitrary terminals.
Solution:   Always set 'ttyfast'. (closes #11549)
diff --git a/runtime/doc/os_vms.txt b/runtime/doc/os_vms.txt
index b2a1590..8ba12ba 100644
--- a/runtime/doc/os_vms.txt
+++ b/runtime/doc/os_vms.txt
@@ -458,18 +458,11 @@
 
 Vim will also recognize that they are fast terminals.
 
-If you have some annoying line jumping on the screen between windows add to
-your .vimrc file: >
-
-	set ttyfast	" set fast terminal
-
-Note: if you're using Vim on remote host or through a very slow connection, it's
-recommended to avoid the fast terminal option with: >
+If you're using Vim on remote host or through a very slow connection, you
+might want to reset fast terminal option with: >
 
 	set nottyfast   " set terminal to slow mode
 
-(Zoltan Arpadffy, Vim 5.6)
-
 
 8.7 Hex-editing and other external tools