[jdk11u-dev] RFR: 8266881: Enable debug log for SSLEngineExplorerMatchedSNI.java

[Goetz Lindenmaier]

I backport this for parity with 11.0.17-oracle.

-------------

Commit messages:
 - Backport 266702451db57c4f006f22601288174cc0613339

Changes: https://git.openjdk.org/jdk11u-dev/pull/1166/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1166&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8266881
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1166.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1166/head:pull/1166

PR: https://git.openjdk.org/jdk11u-dev/pull/1166