Improved error message for wrong argument count.
Improved error message for wrong argument count.

Fixes #2456

arkpar/solidity,shahankhatch/solidity,chriseth/solidity-doc-test,chriseth/solidity,debris/solidity,ethers/solidity,ruchevits/solidity,douglas-larocca/solidity,ruchevits/solidity,vaporry/solidity,gluk256/solidity,ruchevits/solidity,ruchevits/solidity,LefterisJP/solidity,LianaHus/solidity