YR_RE_SCAN_LIMIT changed from 4096 to 1024 in 4.5.3

**Describe the bug** The YR_RE_SCAN_LIMIT constant was modified from 4096 to 1024 between 4.5.2 and 4.5.3. This changes the behavior of the regex matcher and causes some rules that used to match to no longer match. This change was not documented and part of a PR that does not seem related, which probably indicates it wasn't an intended change: https://github.com/VirusTotal/yara/pull/2144/files#diff-5bd98e8dd99d56b0c42f746ae74d3488c21185fcd14acce6c54f3a02404adeb6R174 **Expected behavior** The limit should probably stay at 4096 to avoid breaking existing rules.