EBox::CGI::run now supports correct handling of APR::Error

Exceptions of type APR::Error (apache runtime) were not correct handled and thus masked. See http://trac.zentyal.org/attachment/ticket/6195/zentyal.log for a example of this.

I tested it injecting explicitly an APR::Error in the code, because I don't know how to produce a 'natural' one. So there is a small chance of error.