patch 8.1.0159: completion for user names does not work for a prefix.

Problem:    Completion for user names does not work if a prefix is also a full
            matching name. (Nazri Ramliy)
Solution:   Accept both full and partial matches. (Dominique Pelle)
diff --git a/src/version.c b/src/version.c
index c8dde84..e19f35e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    159,
+/**/
     158,
 /**/
     157,