Fix bug in NetworkStorageSession::clientSideCookieCap() found by new libcpp assertions.
<rdar://104963759>
Pull request: https://github.com/WebKit/WebKit/pull/9528
Committed 259775@main (886d4c8f6d38): <https://commits.webkit.org/259775@main> Reviewed commits have been landed. Closing PR #9528 and removing active labels.