Automatically clear the jar and delete the cookie file for re-auth;

if the Client ID within the cookie does not match the Client ID currently used by the application (#107)

twitch.py

@@ -374,7 +374,8 @@ class _AuthState:
             login_form: LoginForm = self._twitch.gui.login
             logger.info("Checking login")
             login_form.update(_("gui", "login", "logging_in"), None)
-            for attempt in range(2):
+            for client_mismatch_attempt in range(2):
+                for invalid_token_attempt in range(2):
                     cookie = jar.filter_cookies(client_info.CLIENT_URL)
                     if "auth-token" not in cookie:
                         self.access_token = await self._oauth_login()
@@ -399,9 +400,16 @@ class _AuthState:
                             validate_response = await response.json()
                             break
                 else:
-                raise RuntimeError("Login verification failure")
-            if validate_response["client_id"] != client_info.CLIENT_ID:
-                raise LoginException("You're using an old cookie file, please generate a new one.")
+                    raise RuntimeError("Login verification failure (step #2)")
+                # ensure the cookie's client ID matches the currently selected client
+                if validate_response["client_id"] == client_info.CLIENT_ID:
+                    break
+                # otherwise, we need to delete the entire cookie file and clear the jar
+                logger.info("Cookie client ID mismatch")
+                jar.clear()
+                COOKIES_PATH.unlink(missing_ok=True)
+            else:
+                raise RuntimeError("Login verification failure (step #1)")
             self.user_id = int(validate_response["user_id"])
             cookie["persistent"] = str(self.user_id)
             logger.info(f"Login successful, user ID: {self.user_id}")