vim-patch:9.1.2075: tests: wrong change to test_ins_complete.vim

Problem:  tests: wrong change to test_ins_complete.vim
          (zeertzjq, after v9.1.2071)
Solution: Revert unintentional changes

https://github.com/vim/vim/commit/28fd7e7702c8d328861b122ba87c41da33e7044b

Co-authored-by: Christian Brabandt <cb@256bit.org>

test/old/testdir/test_ins_complete.vim

@@ -1604,7 +1604,7 @@ func Test_complete_from_unloadedbuf()
   call writefile(['def'], "Xfile2")
   edit Xfile1
   edit Xfile2
-  new | bw
+  new | close
   enew
   bunload Xfile1 Xfile2
   set complete=u
@@ -1643,7 +1643,7 @@ func Test_complete_from_unlistedbuf()
   call writefile(['def'], "Xfile2")
   edit Xfile1
   edit Xfile2
-  new | bw
+  new | close
   bdel Xfile1 Xfile2
   set complete=U
   " complete from an unlisted buffer