RFR: 8291956: Simplify the loop condition in sun.net.httpserver.Request constructor [v4]

[thyecust]

> The condition at line 57 (after while) will evaluate to false
> if startLine == null, so the previous if-condition is covered.

thyecust has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Merge branch 'openjdk:master' into if
 - Merge branch 'openjdk:master' into if
 - update the Copyright year
 - simplify loop contidition
 - Merge branch 'openjdk:master' into if
 - remove redundant if-condition after readLine()
   
   The condition at line 57 (after while) will evaluate to false
   if startLine == null, so the previous if-condition is covered.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/9571/files
  - new: https://git.openjdk.org/jdk/pull/9571/files/368a6666..55f9a39b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9571&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9571&range=02-03

  Stats: 366 lines in 14 files changed: 264 ins; 21 del; 81 mod
  Patch: https://git.openjdk.org/jdk/pull/9571.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9571/head:pull/9571

PR: https://git.openjdk.org/jdk/pull/9571