docs: fix randomaura reference

Author: fnanni-0

contracts/interfaces/IRandomAuRa.sol

@@ -1,11 +1,11 @@
 pragma solidity ^0.4.24;
 
 
-///@dev See https://blockscout.com/poa/core/address/0x67e90a54AeEA85f21949c645082FE95d77BC1E70/contracts
+///@dev See https://blockscout.com/poa/xdai/address/0x5870b0527DeDB1cFBD9534343Feda1a41Ce47766/contracts
 ///@dev Sokol testnet: https://blockscout.com/poa/sokol/address/0x8f2b78169B0970F11a762e56659Db52B59CBCf1B/contracts
 interface IRandomAuRa {
     function currentSeed() external view returns(uint256);
     function isCommitPhase() external view returns(bool);
     function nextCommitPhaseStartBlock() external view returns(uint256);
-    function collectRoundLength() external view returns(uint256); // 40
+    function collectRoundLength() external view returns(uint256);
 }