RFR: 7903936: Update variable names in build.sh documentation

[Oleksii Sylichenko]

Changed variable name `CURL_OPTS` to `CURL_OPTIONS` in the documentation block "Some noteworthy control variables" in `build.sh`. 

`CURL_OPTIONS` is used in the `download_using_curl()` function in `build-support/build-common.sh`.

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Commit messages:
 - Merge branch 'openjdk:master' into fix-curl-error-options
 - Rename CURL_OPTS to CURL_OPTIONS in build.sh

Changes: https://git.openjdk.org/jtreg/pull/238/files
  Webrev: https://webrevs.openjdk.org/?repo=jtreg&pr=238&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903936
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jtreg/pull/238.diff
  Fetch: git fetch https://git.openjdk.org/jtreg.git pull/238/head:pull/238

PR: https://git.openjdk.org/jtreg/pull/238