Remove the "distanceThreshold" parameter from options

[Desrever Nu]

I found "distanceThreshold":0.0, in the sample file (twice).

This parameter is obsolete and should not be set by custodian.

Please delete from sample option files, from the Java model, parser and UI .

wasn't there on master so I am not sure where it came from https://bitbucket.org/JordanLeePeershares/nubottrading/src/0bb0225995a7da75ca816dd2a2be7a0a94704289/NuBot/src/com/nubits/nubot/options/OptionsJSON.java?at=master

nor in setup.md

https://bitbucket.org/JordanLeePeershares/nubottrading/src/d69252c90538a92acb0f40a0367f0a10a207719e/SETUP.md?at=master