RFR: 7368: Update the 8.1 splash to release splash

[Marcus Hirt]

Updated the splash screen.

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Commit messages:
 - 7368: Update the 8.1 splash to release splash

Changes: https://git.openjdk.java.net/jmc/pull/296/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=296&range=00
  Issue: https://bugs.openjdk.java.net/browse/JMC-7368
  Stats: 0 lines in 1 file changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jmc/pull/296.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/296/head:pull/296

PR: https://git.openjdk.java.net/jmc/pull/296