RFR: 8273670: Remove weak etypes from default krb5 etype list [v2]

[Weijun Wang]

> This code change removes weak etypes from the default list so it's safer to enable one of them. See the corresponding CSR at https://bugs.openjdk.java.net/browse/JDK-8274207 for more explanation. BTW, please review the CSR as well.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  some rewrite

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5654/files
  - new: https://git.openjdk.java.net/jdk/pull/5654/files/6abcd5bf..7937b069

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5654&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5654&range=00-01

  Stats: 55 lines in 2 files changed: 11 ins; 24 del; 20 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5654.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5654/head:pull/5654

PR: https://git.openjdk.java.net/jdk/pull/5654