Multiple encrypted XML elements fail crypto coverage check

Hello colleagues,

I probably found a bug in org.apache.cxf.ws.security.wss4j.CryptoCoverageChecker.

• Issue: SOAP XML message encryption coverage checking for more than 1 XML elements does not work. If only 1 XML element encryption coverage is checked, everything works fine.
• Symptoms: CryptoCoverageUtil.matchElement(Collection<WSDataRef>, CoverageScope, Element) compares objects via references (r.getProtectedElement() == el) but they are always different objects
• Reproducer JUnit tests are provided on GitHub: greatit/crypto-coverage-test

Fixing the issue would be much appreciated. Thank you.