Handle `IGChallengeError` when logging in via FB (#87)

* Handle `IGChallengeError` when logging in via FB

* Fix log where username is unknown

Co-authored-by: Tulir Asokan <tulir@maunium.net>

* Fix formatting

---------

Co-authored-by: Tulir Asokan <tulir@maunium.net>

mautrix_instagram/web/provisioning_api.py

@@ -782,6 +782,11 @@ class ProvisioningAPI:
             return self._2fa_required(user, "<facebook credentials>", state, e)
         except IGCheckpointError as e:
             return self._checkpoint_error(user, "<facebook credentials>", e, after="facebook auth")
+        except IGChallengeError as e:
+            self.log.debug(
+                "%s logged in with facebook credentials, but got a challenge", user.mxid
+            )
+            return await self.start_checkpoint(user, state, api, e, after="facebook auth")
         except IGConsentRequiredError as e:
             return self._consent_error(user, "<facebook credentials>", e, after="facebook auth")
         except Exception as e: