Avoid venv activate failure

Change-Id: I361b74d05eea051e75757571cb3ce891cc957f61
diff --git a/jjb/nolabs/handle-booking.sh b/jjb/nolabs/handle-booking.sh
index 30f82d5..a9fa892 100644
--- a/jjb/nolabs/handle-booking.sh
+++ b/jjb/nolabs/handle-booking.sh
@@ -10,7 +10,9 @@
 sudo apt install -y virtualenv jq > /dev/null
 /bin/rm -rf $NOLABS_VENV && mkdir -p $NOLABS_VENV
 virtualenv -p python3 $NOLABS_VENV > /dev/null
+set +u
 source $NOLABS_VENV/bin/activate > /dev/null
+set -u
 pip install httpie > /dev/null
 
 # check if the booking is cancelled or not
@@ -37,7 +39,9 @@
 cat $NOLABS_USER_SSHPUBKEY
 echo "-------------------------------------------------"
 
+set +u
 deactivate
+set -u
 # get the specific patch
 cd $WORKSPACE
 git fetch "https://gerrit.nordix.org/infra/engine" $GERRIT_REFSPEC && git checkout FETCH_HEAD
@@ -49,7 +53,9 @@
 
 cd $WORKSPACE
 
+set +u
 source $NOLABS_VENV/bin/activate > /dev/null
+set -u
 ENGINE_VERSION=$(git rev-parse HEAD)
 cd $WORKSPACE/.cache/repos/swconfig
 SCENARIO_VERSION=$(git rev-parse HEAD)