patch 9.0.2042: Test_cq_zero_exmode fails without channel feature

Problem:  Test_cq_zero_exmode fails without channel feature
Solution: Make the test check the channel feature

closes: #13365

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_startup.vim b/src/testdir/test_startup.vim
index 6780205..1a81318 100644
--- a/src/testdir/test_startup.vim
+++ b/src/testdir/test_startup.vim
@@ -1353,6 +1353,8 @@
 
 " Test that -cq works as expected
 func Test_cq_zero_exmode()
+  CheckFeature channel
+
   let logfile = 'Xcq_log.txt'
   let out = system(GetVimCommand() .. ' --clean --log ' .. logfile .. ' -es -X -c "argdelete foobar" -c"7cq"')
   call assert_equal(8, v:shell_error)