fix: manual ban causes an undefined log entry (#1779)

[rsercano]

resolves #1779

[raladev]

• [x] got different ban message (not node ${nodePubKey} was banned manually) it seems that ${ReputationEvent[events[0]]} is not empty

  21/10/2020 17:02:54.880 [RPC] trace: received call /xudrpc.Xud/Ban
  21/10/2020 17:02:54.889 [DB] trace: Executing (default): SELECT `id`, `event`, `nodeId`, `createdAt` FROM `reputationEvents` AS `ReputationEvent` WHERE `ReputationEvent`.`nodeId` = 1 ORDER BY `ReputationEvent`.`createdAt` DESC;
  21/10/2020 17:02:54.893 [DB] trace: Executing (default): UPDATE `nodes` SET `banned`=$1,`updatedAt`=$2 WHERE `id` = $3
  21/10/2020 17:02:54.897 [P2P] info: node 03ece33a30db1dbce4b62fa96a5e9541138a24997ef5672eebed2d332270e39542 was banned due to ManualBan
  21/10/2020 17:02:54.897 [P2P] debug: Peer 03ece33a30db1dbce4b62fa96a5e9541138a24997ef5672eebed2d332270e39542 (OzoneYellow): closing socket. reason: Banned

[rsercano]

In my case it was empty @raladev, but I added the ManualBan check too.