Look at the spelling: it would have rhymed with 'honey'. It's a pretty common phenomenon: we (Americans anyway) don't talk about 'cocks' and 'asses' anymore, we have roosters and donkeys.
The OED has a pronunciation history:
The usual current pronunciation with long ō ( /əʊ/ ) seems to have become established during the course of the 19th cent., and may in part be a spelling pronunciation reflecting the rarity of the word in general use in standard English at this date, when it may have been most familiar to many from use in the Bible (and especially in the Psalms) as the name of a foreign animal. However, this pronunciation is likely to have been reinforced by the desire to avoid association with 'cunt' and related words (compare 'cunny'), especially in a religious context.
The OED has a pronunciation history:
The usual current pronunciation with long ō ( /əʊ/ ) seems to have become established during the course of the 19th cent., and may in part be a spelling pronunciation reflecting the rarity of the word in general use in standard English at this date, when it may have been most familiar to many from use in the Bible (and especially in the Psalms) as the name of a foreign animal. However, this pronunciation is likely to have been reinforced by the desire to avoid association with 'cunt' and related words (compare 'cunny'), especially in a religious context.