Fix put_events max size
Fix put_events max size

cosmo0920/fluent-plugin-cloudwatch-logs,sorah/fluent-plugin-cloudwatch-logs,ephemeralsnow/fluent-plugin-cloudwatch-logs,waniji/fluent-plugin-cloudwatch-logs,ryotarai/fluent-plugin-cloudwatch-logs,chiefy/fluent-plugin-cloudwatch-logs