Problem after start moneropool.exe on Ubuntu 14.04

Hello!
After start pool i'm have error. Pool not starting
```
[10.07.2017 12:47:50] [Thread Count : 12]Current pool hashrate : not number Hashes/Second
[10.07.2017 12:47:50] [Thread Count : 12]System.OverflowException: Number overflow.
at System.Int64.System.IConvertible.ToInt32 (IFormatProvider provider) [0x00000] in :0
at System.Convert.ToInt32 (System.Object value, IFormatProvider provider) [0x00000] in :0
at Newtonsoft.Json.Linq.JToken.op_Explicit (Newtonsoft.Json.Linq.JToken value) [0x00000] in :0
at MoneroPool.BackgroundStaticUpdater+c__async0.MoveNext () [0x00000] in :0
```
Any idea how fix this?

Start by reproducing the failure on Ubuntu 14.04 and tracing BackgroundStaticUpdater.Start from the stack trace, especially the Newtonsoft.Json conversion that reaches Int32. The fix is complete when moneropool.exe starts without the System.OverflowException and reports a numeric pool hashrate.

Written by the indexing model from the issue text.