Add the change output to owned_txfilter so its entry in db will
get a confirmation_height when detected in a block by filter_block_txs
before this commit, after a 'withdraw' command, 'listfunds' would
not show our change outputs as confirmed
Modified the log message in wallet_extract_owned_outputs to
append 'CONFIRMED' when it is called with a blockheight arg.
To make distinction between (1st call) when adding owned output to the
db and (2th call) when confirmed in block.