mjr-fix-firmware-note

The doc incorrectly stated the "this app is not genuine" message began appearing with firmware 1.6.0. I've removed the reference to that firmare.

README.md

@@ -1048,7 +1048,7 @@ Note that you may still see warnings similar to `Unexpected sequence number (exp
 
 ### Command Line Installations: "This app is not genuine"
 
-If you install a Ledger application, such as Tezos Wallet or Tezos Baking, outside of Ledger Live you will see the message "This app is not genuine" followed by an Indentifier when opening the app. This message began appearing with Ledger firmware 1.6.0 as a warning to the user whenever an application is installed outside Ledger Live. Ledger signs the applications available in Ledger Live to verify their authenticity, but the same applications available elsewhere, such as from this repo, are not signed by Ledger. As a result, the user is warned that the app is not "genuine", i.e. signed by Ledger. This helps protect users who may have accidentally downloaded an app from a malicious client without knowing it. Note that the application available from this repo's [releases page](https://github.com/obsidiansystems/ledger-app-tezos/releases/tag/v2.2.7) is otherwise no different from the one downloaded from Ledger Live.
+If you install a Ledger application, such as Tezos Wallet or Tezos Baking, outside of Ledger Live you will see the message "This app is not genuine" followed by an Indentifier when opening the app. This message is generated by the device firmware as a warning to the user whenever an application is installed outside Ledger Live. Ledger signs the applications available in Ledger Live to verify their authenticity, but the same applications available elsewhere, such as from this repo, are not signed by Ledger. As a result, the user is warned that the app is not "genuine", i.e. signed by Ledger. This helps protect users who may have accidentally downloaded an app from a malicious client without knowing it. Note that the application available from this repo's [releases page](https://github.com/obsidiansystems/ledger-app-tezos/releases/tag/v2.2.7) is otherwise no different from the one downloaded from Ledger Live.
 
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