Wrong hashrate statistics on x16r
### Description

Wrong hashrate statistics on x16r

### Steps to Reproduce

1. Connect miners to pool
2. Start mining
3. Watch the DB entries in minerstats

### Expected behavior

Hashrate should be something similar to the reported value in the miner.

### Actual behavior

Hashrate is about 3.5 - 4.0 times lower then the reporterd hashrate in the miner.
Ex: miner: 97.90, DB: 26285122.3782077 = 25.06

### Reproduces how often

100%

### Version

Dev version from 2018-04-18

### Additional Information

I searched this repo and for another coin it was suggested to just apply a multiplier to the DB values to make them more in line with that the miner reports. Is it the same case here?

// Update
No reported hashrate improvement after running a miner on it for almost 24h.
The API also reports the low hashrate, seems to be using the same values as the DB.
