RFR: 8266774: System property values for stdout/err on Windows UTF-8

[Naoto Sato]

Please review this small fix to Windows system property init code. This is leftover from the support for `Console.charset()` method, where it lacked to initialize `sun.stdout/err.encoding` to `UTF-8` for the code page `cp65001`.  The fix has been manually verified, but no automated test case is provided, as automatically setting `UTF-8` for the system locale on Windows test machine seems not possible.

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Commit messages:
 - 8266774: System property values for stdout/err on Windows UTF-8

Changes: https://git.openjdk.java.net/jdk/pull/3931/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3931&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266774
  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3931.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3931/head:pull/3931

PR: https://git.openjdk.java.net/jdk/pull/3931