Fix telnyx auth api response parsing #2036

Job	Run time
check	3m 9s
clippy	27s
rustfmt	6s
test	7m 1s
audit	8s
integration-test-althea-payment	10m 46s
integration-test-db-migration	6m 27s
integration-test-debts	9m 20s
integration-test-five-nodes	7m 14s
integration-test-eth-payments	11m 34s
integration-test-multi-exit	6m 51s
integration-test-validate-contract	5m 59s
cross-armv7	48s
cross-aarch64	33s
	1h 10m 23s

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