Fix typo in script

Change-Id: Iacf6fa9761a20113cd07a94d697f74499ec00625
diff --git a/jjb/onos/onos-docker-build.sh b/jjb/onos/onos-docker-build.sh
index b0e1753..12714a2 100644
--- a/jjb/onos/onos-docker-build.sh
+++ b/jjb/onos/onos-docker-build.sh
@@ -13,7 +13,7 @@
 # set up release build credentials
 . onos-build-credentials
 
-on# get the sources
+# get the sources
 git checkout $GERRIT_BRANCH
 git checkout -b docker $ONOS_TAG