[DEVOPS-978] Expose disableClientAuth in sample-wallet-config.nix (#3736)
[DEVOPS-978] Expose disableClientAuth in sample-wallet-config.nix (#3736)

Some 3rd parties are accustomed to running without the client cert
authentication feature. This advertises the option to disable it in
the sample wallet config.
input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl