Revert "add the prechecker for weserv with HEAD request"
Revert "add the prechecker for weserv with HEAD request"

This reverts commit 8efb209c457b49d8fed5085bf69b20cdf7c7997d.
in 'no-cors' mode, JavaScript can't check the Request.ok property by always false.

Tosuke/Misskey-Web,armchair-philosophy/Misskey-Web,armchair-philosophy/Misskey-Web,Tosuke/Misskey-Web,misskey-delta/Misskey-Web,Tosuke/Misskey-Web,misskey-delta/Misskey-Web,Tosuke/Misskey-Web,misskey-delta/Misskey-Web,armchair-philosophy/Misskey-Web