enable exceptions

git-svn-id: svn+ssh://svn.savannah.nongnu.org/gap/trunk@2774 d25b4930-3292-e311-b074-0010c6de5da8
enable exceptions

git-svn-id: svn+ssh://svn.savannah.nongnu.org/gap/trunk@2775 d25b4930-3292-e311-b074-0010c6de5da8