Fix Account linking page (#33325)

Fix password form missing whilst linking account even with
`ENABLE_PASSWORD_SIGNIN_FORM = true`.

Remove redundant empty box in account linking sign up page when
`LinkAccountMode` is true.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/user/auth/signup_inner.tmpl

@@ -59,12 +59,12 @@
 </div>
 
 <div class="ui container fluid">
+	{{if not .LinkAccountMode}}
 	<div class="ui attached segment header top tw-flex tw-flex-col tw-items-center">
-		{{if not .LinkAccountMode}}
 		<div class="field">
 			<span>{{ctx.Locale.Tr "auth.already_have_account"}}</span>
 			<a href="{{AppSubUrl}}/user/login">{{ctx.Locale.Tr "auth.sign_in_now"}}</a>
 		</div>
-		{{end}}
 	</div>
+	{{end}}
 </div>