Update jenkins to 2.121.3 version

Update jenkins in the product to 2.121.3 version
diff --git a/Dockerfile b/Dockerfile
index bb177b7..05a1b54 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -50,10 +50,10 @@
 
 # jenkins version being bundled in this docker image
 ARG JENKINS_VERSION
-ENV JENKINS_VERSION ${JENKINS_VERSION:-2.104}
+ENV JENKINS_VERSION ${JENKINS_VERSION:-2.121.3}
 
 # jenkins.war checksum, download will be validated using it
-ARG JENKINS_SHA=51724ecb3c287d13679d9c1bde72552283928b17f49861fe2bfd337fbbfb95a0
+ARG JENKINS_SHA=50fbce11fa147d0ecd9ecf36cdae83ef795fb7d4776f33b5ea13bc15bf6e3c13
 
 # Can be used to customize where jenkins.war get downloaded from
 ARG JENKINS_URL=https://repo.jenkins-ci.org/public/org/jenkins-ci/main/jenkins-war/${JENKINS_VERSION}/jenkins-war-${JENKINS_VERSION}.war