Potential memory leak in ParameterizedMessage

[Adrien Grand]

Hello,

While reviewing a heap dump a couple weeks ago, I found that log4j was
using more memory than I would expect, and this turned out to come from a
static ThreadLocal in ParameterizedMessage. Could someone look at the
following issue?
https://issues.apache.org/jira/browse/LOG4J2-1858

Thanks.

Adrien