fix: use correct env variable key for did:empe driver in .env file

Author: BernhardFuchs

.env

@@ -69,4 +69,4 @@ uniresolver_driver_did_near_contract_id=neardti.testnet
 uniresolver_driver_did_near_rpc_url=https://rpc.testnet.near.org
 uniresolver_driver_did_near_network_id=testnet
 
-DID_METHODS=[{"method":"empe","network":"testnet","url":"https://rpc-testnet.empe.io"},{"method":"empe","url":"https://rpc.empe.io"}]
+uniresolver_driver_did_empe_did_methods=[{"method":"empe","network":"testnet","url":"https://rpc-testnet.empe.io"},{"method":"empe","url":"https://rpc.empe.io"}]