Add a warning to the Log4jFuzzer
Add a warning to the Log4jFuzzer

At least in theory, when run on an old JDK, this fuzzer could randomly
pick up log4j exploits.

CodeIntelligenceTesting/jazzer,CodeIntelligenceTesting/jazzer,CodeIntelligenceTesting/jazzer,CodeIntelligenceTesting/jazzer,CodeIntelligenceTesting/jazzer