Removed redundant throws

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1562755 13f79535-47bb-0310-9956-ffa450edef68
Allow declaring subclasses in exceptions.

The eclipse plugin for checkstyle sometimes flagged this as errors.
Since we have decided to be explicit in the Javadoc, we have to allow
it.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1562756 13f79535-47bb-0310-9956-ffa450edef68