Problem: Cannot have buffer-local value for 'completeopt'
(Nick Jensen).
Solution: Make 'completeopt' global-local (zeertzjq).
Also for some reason test Test_ColonEight_MultiByte seems to be failing
sporadically now. Let's mark it as flaky.
fixes: #5487closes: #14922
Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>