patch 8.2.2130: Insert mode completion messages end up in message history

Problem:    Insert mode completion messages end up in message history.
Solution:   Set msg_hist_off. (closes #7452
diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 5e2bebb..b1a2a9e 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -114,7 +114,7 @@
   set omnifunc=Omni
   new
   exe "normal Gofind -\<C-x>\<C-o>"
-  call assert_equal("\n-\nmatch 1 of 2", execute(':2mess'))
+  call assert_equal("find -help", getline('$'))
 
   bwipe!
   delfunc Omni
@@ -714,4 +714,16 @@
   set completeslash=
 endfunc
 
+" Test to ensure 'Scanning...' messages are not recorded in messages history
+func Test_z1_complete_no_history()
+  new
+  messages clear
+  let currmess = execute('messages')
+  setlocal dictionary=README.txt
+  exe "normal owh\<C-X>\<C-K>"
+  exe "normal owh\<C-N>"
+  call assert_equal(currmess, execute('messages'))
+  close!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab