patch 8.2.2355: stray test failure on Appveyor

Problem:    Stray test failure on Appveyor.
Solution:   Finish insert command.

Author: brammool

src/testdir/test_autocmd.vim

@@ -1639,14 +1639,14 @@ func Test_BufReadCmd()
 endfunc
 
 func SetChangeMarks(start, end)
-  exe a:start. 'mark ['
-  exe a:end. 'mark ]'
+  exe a:start .. 'mark ['
+  exe a:end .. 'mark ]'
 endfunc
 
 " Verify the effects of autocmds on '[ and ']
 func Test_change_mark_in_autocmds()
   edit! Xtest
-  call feedkeys("ia\<CR>b\<CR>c\<CR>d\<C-g>u", 'xtn')
+  call feedkeys("ia\<CR>b\<CR>c\<CR>d\<C-g>u\<Esc>", 'xtn')
 
   call SetChangeMarks(2, 3)
   write

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2355,
 /**/
     2354,
 /**/