Remove redundant and erroneous function call from FA1.2 Doc Tutorial

[GradeyCullins]

Problem

While learning about the Tezos developer ecosystem, I've discovered what I believe to be an error in the documentation page found here:

https://assets.tqtezos.com/docs/token-contracts/fa12/2-fa12-ligo/

The code to highlight is:

const { InMemorySigner, importKey } = require("@taquito/signer")
const fs = require("fs")
const { email, password, mnemonic, secret } = JSON.parse(
  fs.readFileSync("./faucet.json").toString()
)

const Tezos = new TezosToolkit("https://api.tez.ie/rpc/edonet")
Tezos.setProvider({ signer: new InMemorySigner() })

importKey(Tezos, email, password, mnemonic.join(" "), secret)

I believe the call to Tezos.setProvider(...) is unnecessary for two reasons:

1. The documentation for importKey states that the function has a "side-effect" of setting the Tezos instance's signer to the InMemorySigner making the Tezos.setProvider(... call redundant.
2. Per the most current docs, it is incorrect to call the InMemorySigner constructor with no arguments.

Solution

My pull request removes the redundant call and the InMemorySigner import.