Remove unnecessary template helper DisableGravatar (#26386)

And one "AllowedUserVisibilityModes" was missing, add it.

Co-authored-by: Giteabot <teabot@gitea.io>

templates/user/settings/profile.tmpl

@@ -99,7 +99,7 @@
 		<div class="ui attached segment">
 			<form class="ui form" action="{{.Link}}/avatar" method="post" enctype="multipart/form-data">
 				{{.CsrfTokenHtml}}
-				{{if not (DisableGravatar $.Context)}}
+				{{if not .DisableGravatar}}
 				<div class="inline field">
 					<div class="ui radio checkbox">
 						<input name="source" value="lookup" type="radio" {{if not .SignedUser.UseCustomAvatar}}checked{{end}}>