patch 8.0.1171: popup test is still a bit flaky

Problem:    Popup test is still a bit flaky.
Solution:   Change term_wait() calls. (Ozaki Kiichi)
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 0dfa956..fdd51de 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -645,9 +645,8 @@
   endif
   let g:buf = term_start([$VIMPROG, '--clean', '-c', 'set noswapfile'], {'term_rows': h / 3})
   call term_sendkeys(g:buf, (h / 3 - 1)."o\<esc>G")
-  call term_wait(g:buf, 100)
   call term_sendkeys(g:buf, "i\<c-x>")
-  call term_wait(g:buf, 100)
+  call term_wait(g:buf, 200)
   call term_sendkeys(g:buf, "\<c-v>")
   call term_wait(g:buf, 100)
   " popup first entry "!" must be at the top