Update Hardhat version error message

src/index.ts

@@ -7,16 +7,13 @@ try {
 
 ERROR
 
-Please upgrade your hardhat version to 2.11 or above.
-This error is generated by plugin "hardhat-tracer" because it is 
-dependent on some features available in hardhat >=2.11.0 <3.0.0.
+This version of "hardhat-tracer" only works with versions of
+Hardhat previous to 2.21.0.
 
-npm i hardhat@latest
-
-or
-
-yarn add hardhat@latest
+A new version compatible with the latest Hardhat will be released soon.
 
+In the meantime, downgrade Hardhat to 2.20.1, or remove "hardhat-tracer"
+from your Hardhat config.
 `
   );
   process.exit(1);