RFR: 8295945: Revert unintended change to copyright start year

[Ambarish Rapte]

A quick fix to correct the created copyright year. 
The created year in the header was unintentionally modified previously from 2021 to 2017.

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Commit messages:
 - correct copyright year

Changes: https://git.openjdk.org/jfx/pull/1496/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1496&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295945
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1496.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1496/head:pull/1496

PR: https://git.openjdk.org/jfx/pull/1496