patch 9.0.1022: suspend test fails on Mac OS when suspending Vim

Problem:    Suspend test fails on Mac OS when suspending Vim.
Solution:   Make 'keyprotocol' empty.
diff --git a/src/testdir/test_suspend.vim b/src/testdir/test_suspend.vim
index ef8fea5..5175c0f 100644
--- a/src/testdir/test_suspend.vim
+++ b/src/testdir/test_suspend.vim
@@ -34,7 +34,7 @@
 
   call term_sendkeys(buf, v:progpath
         \               . " --clean -X"
-        \               . " -c 'set nu'"
+        \               . " -c 'set nu keyprotocol='"
         \               . " -c 'call setline(1, \"foo\")'"
         \               . " Xfoo\<CR>")
   " Cursor in terminal buffer should be on first line in spawned vim.
@@ -84,7 +84,7 @@
 
   call term_sendkeys(buf, v:progpath
         \               . " --clean -X"
-        \               . " -c 'set nu'"
+        \               . " -c 'set nu keyprotocol='"
         \               . " -c 'let g:count = 0'"
         \               . " -c 'au VimSuspend * let g:count += 1'"
         \               . " -c 'au VimResume * let g:count += 1'"