Add waiting time to timeout error message

[webmaster128]

In an error case like this it would be interesting to understand how long the client waited for the inclusion of a tx. That allows for interpretation how realistic it is that the tx will make it into a block. E.g. if a chain has 3 second block times and the error says "after 60 seconds" you know that 20 blocks have been created without your transaction. If it says "after 10 seconds" and you have a 6 second block time, that can mean you did not make it in the first block but it is still likely the tx will show up.