[REF] remove first attempt to set currency in repeattransaction flow

[eileenmcnaughton]

Overview

Removes code that no longer does anything

Before

contributionParams['currency'] set from a convoluted variable, but then overwritten in repeattransaction. For completetransaction is is not required as the contribution already has a saved currency

After

Test added, lines removed

Technical Details

The currency is retrieved from the template transaction, these lines are no longer needed, as demonstrated
in the test

Comments

Test cover in edited test & also in testRepeatTransactionWithDifferenceCurrency

[civibot]

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[eileenmcnaughton]

related fail - testRepeatTransactionWithDifferenceCurrency checking but good to note it covers