Update networks/proof_worker.py

networks/proof_worker.py

@@ -44,7 +44,7 @@ class ProofWorker:
             hash = hasher.digest().hex()
             if hash[:diff_len] <= difficulty:
                 return "gAAAAAB" + base
-        return {}  # Returning None if proof token calculation fails
+        return None  # Returning None if proof token calculation fails
 
 
 if __name__ == "__main__":