patch 9.1.1086: completion doesn't work with multi lines

Problem:  completion doesn't work with multi lines
          (Ɓukasz Jan Niemier)
Solution: handle linebreaks in completion code as expected
          (glepnir)

fixes: #2505
closes: #15373

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index 43c5cfe..3614ce3 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -41638,6 +41638,7 @@
 - new digraph "APPROACHES THE LIMIT" using ".="
 - Add the optional {opts} |Dict| argument to |getchar()| to control: cursor
   behaviour, return type and whether or not to simplify the returned key
+- handle multi-line completion as expected
 
 							*added-9.2*
 Added ~