Fix script to match the jenkins job.

Connect sandbox to prod-clone didn't retain the edxapp version even though
it asked the user for it in the jenkins job.

playbooks/edx-east/connect_sandbox.yml

@@ -36,5 +36,5 @@
 
     - name: call update on edx-platform
       shell: >
-        /edx/bin/update edx-platform master
+        /edx/bin/update edx-platform {{ edxapp_version }}
       tags: update_edxapp_mysql_host

util/jenkins/connect-sandbox-to-prod-clone.sh

@@ -38,4 +38,4 @@ if [[ -z $sandbox_to_update ]]; then
 fi
 
 cd $WORKSPACE/configuration/playbooks/edx-east
-ansible-playbook connect_sandbox.yml  -i $sandbox_to_update, -e@${WORKSPACE}/configuration-secure/ansible/vars/clone-db.yml -e EDXAPP_MYSQL_HOST=$EDXAPP_MYSQL_HOST --user ubuntu  -v
+ansible-playbook connect_sandbox.yml  -i $sandbox_to_update, -e@${WORKSPACE}/configuration-secure/ansible/vars/clone-db.yml -e EDXAPP_MYSQL_HOST=$EDXAPP_MYSQL_HOST -e edxapp_version=${edxapp_version} --user ubuntu  -v