Convert .Source.SkipVerify to $cfg.SkipVerify (#23839) (#23899)

Backport #23839 by @yp05327

`Source` doesn't have `SkipVerify`, it is defined in `cfg`

Co-authored-by: yp05327 <576951401@qq.com>

templates/admin/auth/edit.tmpl

@@ -212,7 +212,7 @@
 					<div class="has-tls inline field {{if not .HasTLS}}gt-hidden{{end}}">
 						<div class="ui checkbox">
 							<label><strong>{{.locale.Tr "admin.auths.skip_tls_verify"}}</strong></label>
-							<input name="skip_verify" type="checkbox" {{if .Source.SkipVerify}}checked{{end}}>
+							<input name="skip_verify" type="checkbox" {{if $cfg.SkipVerify}}checked{{end}}>
 						</div>
 					</div>
 					<div class="field">