A pool ledger configuration already exists with the specified name

[Ning-Qing]

Starting the test pool on localhost

docker build -f ci/indy-pool.dockerfile -t indy_pool .
docker run -itd -p 9701-9708:9701-9708 indy_pool

Use ifconfig to get docker inet 172.17.0.1

export TEST_POOL_IP=172.17.0.1
mvn exec:java -Dexec.mainClass=Main

But I am not connected to the pool

Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.0.0:java (default-cli) on project indy-sdk-java-sample: An exception occured while executing the Java class. org.hyperledger.indy.sdk.pool.PoolLedgerConfigExistsException: A pool ledger configuration already exists with the specified name.

env

1. ubuntu 18.04
2. openjdk 11