Jenkinsfile: reduce memory requirements to avoid 137 error codes
diff --git a/pom.xml b/pom.xml
index e210d12..a364de6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -143,7 +143,7 @@
 	      <artifactId>tycho-surefire-plugin</artifactId>
 	      <version>${tycho-version}</version>
 	      <configuration>
-          <argLine>-Xms2g -Xmx2g -XX:MaxDirectMemorySize=4g -XX:+UseG1GC -XX:+UseStringDeduplication -XX:MaxDirectMemorySize=8g -Dstorage.diskCache.bufferSize=2000</argLine>
+          <argLine>-Xmx2g -XX:MaxDirectMemorySize=2g -XX:+UseG1GC -XX:+UseStringDeduplication -Dstorage.diskCache.bufferSize=2000</argLine>
 	      </configuration>
       </plugin>
       <plugin>