Catch the NoClassDefFoundError if it's thrown

[wheelerlaw]

Summary

See #89. It looks like newer versions of the JRE throw a different exception for Class::forName. It used to be ClassNotFoundException but Java 11 appears to be throwing the same exception but wrapped in a NoClassDefFoundError.

Additional Details

n/a

Checklist

Testing

(Remove this checklist and replace it with "N/A - no code changes" if this PR does not modify source code)

• I have manually verified that my code changes do the right thing.
• I have run the tests and verified that my changes do not introduce any regressions.
• I have written unit tests to verify that my code changes do the right thing and to protect my code against regressions

Documentation

(Remove this checklist and replace it with "N/A - no code changes" if this PR does not modify source code)

• I have updated the "Unreleased" section of CHANGELOG.md with a brief description of my changes.
• I have updated code comments - both GroovyDoc/JavaDoc-style comments and inline comments - where appropriate.
• I have read CONTRIBUTING.md and have followed its guidance.

[JustusNBB]

Please release, this error is a headache on JDK 11 ;)

[corporate-gadfly]

Any chance of a 2.1.6 release?

[mrlov]

Please release 🥺