Update dependency @truffle/hdwallet-provider to v2.1.6

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
@truffle/hdwallet-provider (source)	2.1.4 -> 2.1.6

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Release Notes

trufflesuite/truffle

### [`v2.1.6`](https://togithub.com/trufflesuite/truffle/compare/@truffle/hdwallet-provider@2.1.5...@truffle/hdwallet-provider@2.1.6) [Compare Source](https://togithub.com/trufflesuite/truffle/compare/@truffle/hdwallet-provider@2.1.5...@truffle/hdwallet-provider@2.1.6) ### [`v2.1.5`](https://togithub.com/trufflesuite/truffle/compare/@truffle/hdwallet-provider@2.1.4...@truffle/hdwallet-provider@2.1.5) [Compare Source](https://togithub.com/trufflesuite/truffle/compare/@truffle/hdwallet-provider@2.1.4...@truffle/hdwallet-provider@2.1.5)

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Configuration

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