update-python-env: handle empty .python-version

update-python-env.sh

@@ -23,11 +23,13 @@ if [ $res -eq 1 ]; then
 fi
 
 CUR_VENV=$(cat .python-version)
+if [ -n "$CUR_VENV" ]; then
     echo "[*] Removing current virtualenv ($CUR_VENV)"
     pyenv virtualenv-delete -f $CUR_VENV || exit 1
 
     echo "[*] Removing virtualenv named as project ($PROJECT)"
     pyenv virtualenv-delete -f $PROJECT || exit 1
+fi
 
 NEW_VENV=$PY_VER/envs/$PROJECT
 echo "[*] Creating new virtualenv ($NEW_VENV)"