Fix false login state on failed login

Previously, a failed login would change the site-wide navigation so that
it looked like the user was logged in, even though they weren't. This
fixes that.

account.go

@@ -312,7 +312,7 @@ func viewLogin(app *App, w http.ResponseWriter, r *http.Request) error {
 		To            string
 		Message       template.HTML
 		Flashes       []template.HTML
-		Username string
+		LoginUsername string
 	}{
 		pageForReq(app, r),
 		r.FormValue("to"),

pages/login.tmpl

@@ -12,8 +12,8 @@
 	</ul>{{end}}
 
 	<form action="/auth/login" method="post" style="text-align: center;margin-top:1em;" onsubmit="disableSubmit()">
-		<input type="text" name="alias" placeholder="Username" value="{{.Username}}" {{if not .Username}}autofocus{{end}} /><br />
-		<input type="password" name="pass" placeholder="Password" {{if .Username}}autofocus{{end}} /><br />
+		<input type="text" name="alias" placeholder="Username" value="{{.LoginUsername}}" {{if not .LoginUsername}}autofocus{{end}} /><br />
+		<input type="password" name="pass" placeholder="Password" {{if .LoginUsername}}autofocus{{end}} /><br />
 		{{if .To}}<input type="hidden" name="to" value="{{.To}}" />{{end}}
 		<input type="submit" id="btn-login" value="Login" />
 	</form>