patch 8.2.0557: no IPv6 support for channels

Problem:    No IPv6 support for channels.
Solution:   Add IPv6 support. (Ozaki Kiichi, closes #5893)
diff --git a/src/testdir/test_cdo.vim b/src/testdir/test_cdo.vim
index 8a6b746..51800a5 100644
--- a/src/testdir/test_cdo.vim
+++ b/src/testdir/test_cdo.vim
@@ -4,7 +4,7 @@
 CheckFeature quickfix
 
 " Create the files used by the tests
-function SetUp()
+func SetUp()
   call writefile(["Line1", "Line2", "Line3"], 'Xtestfile1')
   call writefile(["Line1", "Line2", "Line3"], 'Xtestfile2')
   call writefile(["Line1", "Line2", "Line3"], 'Xtestfile3')