Improves importer error reporting.
Improves importer error reporting.

Without this patch the importer would abort at the first error, 
then try to unprepare the statement - which again would fail -, 
and the error raised would be the one during unprepare, which
is "transaction abort already."

Now we at least log the first error, but this issue should be 
revisited.  

radiospiel/activerecord-metal