patch 9.1.0000: Vim 9.1 release

Problem:  Need a new release
Solution: Release Vim 9.1

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/os_haiku.txt b/runtime/doc/os_haiku.txt
index fdcf7fe..8fe8c9f 100644
--- a/runtime/doc/os_haiku.txt
+++ b/runtime/doc/os_haiku.txt
@@ -1,4 +1,4 @@
-*os_haiku.txt*	For Vim version 9.0.  Last change: 2020 May 13
+*os_haiku.txt*	For Vim version 9.1.  Last change: 2020 May 13
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar