fix typo in job iteration
diff --git a/tools/jenkins/jenkins_home/build_jenkins.sh b/tools/jenkins/jenkins_home/build_jenkins.sh
index abbdfd1..567a056 100755
--- a/tools/jenkins/jenkins_home/build_jenkins.sh
+++ b/tools/jenkins/jenkins_home/build_jenkins.sh
@@ -42,7 +42,8 @@
 EOF
 
 # Add build numbers
-for job in ${`ls jobs`// / }; do
+JOBS=`ls jobs`
+for job in ${JOBS// / }; do
     if [ ! -e jobs/$job/nextBuildNumber ]; then
         echo 1 > jobs/$job/nextBuildNumber
     fi