Remove precision-loss guards
Remove precision-loss guards

This change was originally made at https://github.com/bancorprotocol/contracts/commit/353c94803ab6411b5cb1d57a4b1df8a877373617 and reverted at https://github.com/bancorprotocol/contracts/commit/2961405e717378fc754add165e3a6d326825754f.
enjin/contracts