The 1841 British edition omitted the again in this verse. It was restored to the LDS text in the second printing of the 1852 LDS edition (probably by reference to the 1840 edition). Earlier, in verse 18, the text refers to the brother of Jared crying unto the Lord, so the use of again is fully appropriate here in verse 22.
Summary: Maintain the again in Ether 2:22, the reading of the earliest text (“and he cried again unto the Lord saying … ”).