Update dependency @nomiclabs/hardhat-ethers to v2.2.1

Author: renovate[bot]

package.json

@@ -19,7 +19,7 @@
 	"author": "",
 	"license": "MPL-2.0",
 	"devDependencies": {
-		"@nomiclabs/hardhat-ethers": "2.1.1",
+		"@nomiclabs/hardhat-ethers": "2.2.1",
 		"@nomiclabs/hardhat-etherscan": "3.1.0",
 		"@nomiclabs/hardhat-waffle": "2.0.3",
 		"@types/chai": "4.3.4",