Bump cron-utils from 7.0.2 to 9.1.3 in /opengrok-indexer

Bumps [cron-utils](https://github.com/jmrozanec/cron-utils) from 7.0.2 to 9.1.3.
- [Release notes](https://github.com/jmrozanec/cron-utils/releases)
- [Commits](jmrozanec/cron-utils@7.0.2...9.1.3)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

opengrok-indexer/pom.xml

@@ -170,7 +170,7 @@ Portions Copyright (c) 2020-2020, Lubos Kosco <[email protected]>.
         <dependency>
             <groupId>com.cronutils</groupId>
             <artifactId>cron-utils</artifactId>
-            <version>7.0.2</version>
+            <version>9.1.3</version>
         </dependency>
         <dependency>
             <groupId>org.jvnet.hudson</groupId>