Fix: Corrected @param typos in NatSpec comments

[rickymcalister]

This is a small fix to remove white space preceding a couple of @param tags in the MintingAccessControl.sol abstract contract.

NatSpec documentation tools (like those used to generate documentation websites from Solidity code) rely on correctly formatted tags like @param, @return, @notice, etc. The non-breaking space may prevent these tools from correctly parsing the comment, which means the parameter documentation might not be displayed correctly in generated documentation.