LTC TestNet orphan everytime 
### Description

The pool only mines orphan blocks on ltc testnet

### Steps to Reproduce

1. setup litecoin
```
rpcuser=litecoinrpc
rpcpassword=pickASecurePassword
rpcport=2300
daemon=1
server=1
gen=1

```
2. run `litecoind -testnet`
3. creat an account and get a address: 
```
$> litecoin-cli -testnet getnewaddress testNetPool
```
get this: `QSfZ5DUrC5yQrWQSnSDS3ZXTDC6g4LnAST`
4. clone and compile miningcore
5. config miningcore:
```json
{
    "logging": {
        "level": "info",
        "enableConsoleLog": true,
        "enableConsoleColors": true,
        "logFile": "",
        "logBaseDirectory": "",
        "perPoolLogFile": false
    },
    "banning": {
        "manager": "integrated",
        "banOnJunkReceive": true,
        "banOnInvalidShares": false
    },
    "notifications": {
        "enabled": true,
        "email": {
            "host": "smtp.example.com",
            "port": 587,
            "user": "user",
            "password": "password",
            "fromAddress": "info@yourpool.org",
            "fromName": "support"
        },
        "admin": {
            "enabled": false,
            "emailAddress": "user@example.com",
            "notifyBlockFound": true
        }
    },
    "persistence": {
        "postgres": {
            "host": "127.0.0.1",
            "port": 5432,
            "user": "miningcore",
            "password": "password",
            "database": "miningcore"
        }
    },
    "paymentProcessing": {
        "enabled": true,
        "interval": 600,
        "shareRecoveryFile": "recovered-shares.txt"
    },
    "pools": [{
      "id": "ltc1",
      "enabled": true,
      "coin": "litecoin",
      "address": "QSfZ5DUrC5yQrWQSnSDS3ZXTDC6g4LnAST",
      "rewardRecipients": [
        {
          "address": "QSfZ5DUrC5yQrWQSnSDS3ZXTDC6g4LnAST",
          "percentage": 1.0
        }
      ],
      "blockRefreshInterval": 500,
      "jobRebroadcastTimeout": 10,
      "clientConnectionTimeout": 600,
      "banning": {
        "enabled": true,
        "time": 600,
        "invalidPercent": 50,
        "checkThreshold": 50
      },
      "ports": {
        "3042": {
          "listenAddress": "0.0.0.0",
          "difficulty": 10,
          "varDiff": {
            "minDiff": 1,
            "targetTime": 10,
            "retargetTime": 30,
            "variancePercent": 30
          }
        }
      },
      "daemons": [
        {
          "host": "127.0.0.1",
          "port": 2300,
          "user": "litecoinrpc",
          "password": "pickASecurePassword"
    }
      ],
      "paymentProcessing": {
        "enabled": true,
        "minimumPayment": 0.5,
        "payoutScheme": "PPLNS",
        "payoutSchemeConfig": {
          "factor": 2.0
        }
      }
    }],
    "api": {
      "enabled": true,
      "listenAddress": "127.0.0.1",
      "port": 4000
  }
}
```
6. start pool and 2 mining rig
7. wait 6hours

### Expected behavior

Not getting orphaned blocks

### Actual behavior

All blocks mined are orphaned : [https://pastebin.com/0ETAsiC7](blocks_tables.csv)

### Reproduces how often

All the time

### Version
master version
**OS**: Antergos Linux x86_64
**Kernel**: 5.0.2-arch1-1-ARCH

