Can’t declare an empty env variable
just don’t declare it
diff --git a/Dockerfile b/Dockerfile
index 0a79897..10c6c0a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,9 +18,6 @@
 # define url prefix for running jenkins behind Apache (https://wiki.jenkins-ci.org/display/JENKINS/Running+Jenkins+behind+Apache)
 ENV JENKINS_PREFIX /
 
-# override JAVA_OPTS using `docker run --env` to pass custom JVM parameters, typically `-D...` system properties 
-ENV JAVA_OPTS ""
-
 # for main web interface:
 EXPOSE 8080