Use explicit log4j version

Resolves #126
is safer, as dependabot can jump in and more reliable as it does not
depend on what version the user has installed.

The current v3 beta versions are not compatible with krill indexer.

Change-Id: I1ae148ee369a7a29b9c69153045136f0adced8b8
diff --git a/pom.xml b/pom.xml
index d19b3d9..34aac10 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,7 +62,7 @@
     <java.version>17</java.version>
     <jersey.version>3.1.5</jersey.version>
     <jackson.version>2.17.0</jackson.version>
-    <log4j.version>[2.19.0,)</log4j.version>
+    <log4j.version>2.23.1</log4j.version>
     <lucene.version>5.0.0</lucene.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
@@ -317,22 +317,35 @@
 	</configuration>
       </plugin>
 
-      <plugin>
-	<groupId>org.codehaus.mojo</groupId>
-	<artifactId>exec-maven-plugin</artifactId>
-	<version>3.2.0</version>
-	<executions>
-	  <execution>
-	    <goals>
-	      <goal>java</goal>
-	    </goals>
-	  </execution>
-	</executions>
-	<configuration>
-	  <mainClass>de.ids_mannheim.korap.server.Node</mainClass>
-	</configuration>
-      </plugin>
-
+        <plugin>
+            <groupId>org.codehaus.mojo</groupId>
+            <artifactId>exec-maven-plugin</artifactId>
+            <version>3.2.0</version>
+            <executions>
+                <execution>
+                    <goals>
+                        <goal>java</goal>
+                    </goals>
+                    <configuration>
+                        <mainClass>de.ids_mannheim.korap.server.Node</mainClass>
+                    </configuration>
+                </execution>
+                <execution>
+                    <id>run-krill-indexer-jar</id>
+                    <phase>verify</phase>
+                    <goals>
+                        <goal>exec</goal>
+                    </goals>
+                    <configuration>
+                        <executable>java</executable>
+                        <arguments>
+                            <argument>-jar</argument>
+                            <argument>${project.build.directory}/Krill-Indexer.jar</argument>
+                        </arguments>
+                    </configuration>
+                </execution>
+            </executions>
+        </plugin>
     </plugins>
 
     <resources>