modules/context/auth.go: fix redirect loop (#5965)

Closes #5815

modules/context/auth.go

@@ -42,7 +42,7 @@ func Toggle(options *ToggleOptions) macaron.Handler {
 			// prevent infinite redirection
 			// also make sure that the form cannot be accessed by
 			// users who don't need this
-			if ctx.Req.URL.Path == setting.AppSubURL+"/user/settings/change_password" {
+			if ctx.Req.URL.Path == "/user/settings/change_password" {
 				if !ctx.User.MustChangePassword {
 					ctx.Redirect(setting.AppSubURL + "/")
 				}