ledger-copy-transaction-at-point: leave point in better place for editing

I love `ledger-copy-transaction-at-point`, but at the end of the function, it leaves the point right on top of the dollar-sign ($), so I always have to move forward 2 characters to edit the actual amount. This change saves me two keystrokes :-) But, I completely understand if you'd prefer to keep the original behavior... just wanted to share. Thanks!