Bump log4j-core from 2.13.2 to 2.15.0

Bumps log4j-core from 2.13.2 to 2.15.0.

---
updated-dependencies:
- dependency-name: org.apache.logging.log4j:log4j-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -26,7 +26,7 @@
         <compatibility.skip>true</compatibility.skip>
         <bintray.package>elasticsearch-addon</bintray.package>
         <hibernate-validator.version>6.1.5.Final</hibernate-validator.version>
-        <log4j.version>2.13.2</log4j.version>
+        <log4j.version>2.15.0</log4j.version>
     </properties>
 
     <build>