Fix abort while trying to catch hidden symbol

According to exiv2 upstream, we should catch the base-class.

see https://github.com/Exiv2/exiv2/issues/947

Fixes #42
2 jobs for 42-crash-on-freebsd-because-of-the-use-of-exiv2-error in 8 minutes and 54 seconds
Status Job ID Name Coverage
  Build
passed #348773
build-job

00:05:20

 
  Test
passed #348774
test

00:03:33