RFR: 2544: SKARA bot ignores GitHub comments in some cases

[Zhao Song]

When querying pull requests in GitHub, we should query all the pull requests instead of the first page, otherwise, in some cases, some prs will be ignored.

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Commit messages:
 - SKARA-2544

Changes: https://git.openjdk.org/skara/pull/1736/files
  Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1736&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-2544
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/skara/pull/1736.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1736/head:pull/1736

PR: https://git.openjdk.org/skara/pull/1736