fixed an issue with callbacks

src/main.py

@@ -1,5 +1,5 @@
 import os
-from flask import Flask, render_template, redirect, url_for
+from flask import Flask, render_template, redirect, request, url_for
 from flask_discord import DiscordOAuth2Session, requires_authorization, AccessDenied, Unauthorized
 from config import load_config
 
@@ -31,6 +31,7 @@ def me():
 
 @app.route("/login/")
 def login():
+    discord.redirect_uri = request.host + "/callback/"
     return discord.create_session(scope=['identify', 'guilds', 'guilds.members.read'])
 
 @app.route("/logout/")