[jdk11u-dev] RFR: 8300751: [17u] Remove duplicate entry in javac.properties

[Shruthi]

OpenJDK PR : https://github.com/openjdk/jdk17u-dev/pull/1096
OpenJDK bug : https://bugs.openjdk.org/browse/JDK-8300751

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Commit messages:
 - Backport f504e532a6be6ac6f9b1983d4e38f18a63a8e778

Changes: https://git.openjdk.org/jdk11u-dev/pull/1865/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1865&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300751
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1865.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/1865/head:pull/1865

PR: https://git.openjdk.org/jdk11u-dev/pull/1865