New Pull request: abortTransaction message on EXECUTED is incorrect

[GESCONSULTOR - Óscar Bou]

Hi folks!

I’ve created a new pull request on Github improving current exception 
formatting when thrown on the EXECUTED phase.

You can find it on [1].

HTH,

Oscar

[1] https://github.com/apache/isis/pull/19 
<https://github.com/apache/isis/pull/19>