Bump version to 2.3.19

Author: thiagoloureiro

charts/graylog/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v2
 name: graylog
 home: https://www.graylog.org
-version: 2.3.18
+version: 2.3.19
 appVersion: 6.3.3
 description: Graylog is the centralized log management solution built to open
   standards for capturing, storing, and enabling real-time analysis of terabytes