Jupyter: Fix start script to use ${PWD} instead of the incorrect ${CWD}.

Author: brycelelbach

brev/jupyter-start.bash

@@ -5,7 +5,7 @@
 mkdir -p /accelerated-computing-hub/logs
 
 # Set the preferred directory to the current working directory, which is set by Docker Compose.
-ARGS="--ServerApp.preferred_dir=${CWD}"
+ARGS="--ServerApp.preferred_dir=${PWD:-/}"
 
 if [ -n "${1}" ]; then
   ARGS="--LabApp.default_url=${1}"