Fix invoice asyncio wrapper (#113)

* mypy: fix lightning backend warnings

* fix asyncio invoice creation

* ignore weird mypy error

cashu/mint/startup.py

@@ -8,16 +8,15 @@ from loguru import logger
 from cashu.core.db import Database
 from cashu.core.migrations import migrate_databases
 from cashu.core.settings import CASHU_DIR, LIGHTNING, MINT_PRIVATE_KEY
-from cashu.lightning.lnbits import LNbitsWallet
+from cashu.lightning.lnbits import LNbitsWallet  # type: ignore
 from cashu.mint import migrations
 from cashu.mint.ledger import Ledger
 
 ledger = Ledger(
     db=Database("mint", "data/mint"),
     seed=MINT_PRIVATE_KEY,
-    # seed="asd",
     derivation_path="0/0/0/0",
-    lightning=LNbitsWallet() if LIGHTNING else None,
+    lightning=LNbitsWallet(),
 )