Migrating BoucerProxy.sol to Solidity 0.5.0+

[Standaa]

Hello @austintgriffith ,
I am trying to migrate the contract to the latest Solidity version. My understanding is that 0.5.0+ enforces stronger types. I managed to fix most errors except one, line 90.
I replaced this require(msg.sender.call.value(rewardAmount).gas(36000)()); with require(msg.sender.call.value(rewardAmount).gas(36000)("")); as recommended in the breaking changes section of the docs.
However I am still returned the following error : TypeError: No matching declaration found after argument-dependent lookup. require(msg.sender.call.value(rewardAmount).gas(36000)(""));
I am not sure what the problem is. I tried to search on S.O & Goog and from the different posts I read, it seems related to parameters not being of the good type.
I am a bit clueless as to how to fix that error though.
Do you have any ideas ?
Many thanks.