Change nucleus image to use nucleus name instead of openmme in comac-in-a-box test

Change-Id: Ib6119a62877ad17fd920f153b62509bc4a1b8367
diff --git a/jjb/pipeline/comac-in-a-box-github.groovy b/jjb/pipeline/comac-in-a-box-github.groovy
index 881257a..eb07b42 100644
--- a/jjb/pipeline/comac-in-a-box-github.groovy
+++ b/jjb/pipeline/comac-in-a-box-github.groovy
@@ -102,7 +102,7 @@
             echo "Changed mme tag: ${docker_tag}"
           elif [ "${params.project}" = "Nucleus" ]
           then
-            sed -i "s;mme: .*;mme: \\"openmme:${docker_tag}\\";" ${omec_cp} # nucleus shares the same docker name as openmme.
+            sed -i "s;mme: .*;mme: \\"nucleus:${docker_tag}\\";" ${omec_cp}
             echo "Changed mme tag: ${docker_tag}"
           elif [ "${params.project}" = "ngic-rtc" ]
           then