remove the option of sourcing manage.sh

manage.sh

 BASE_DIR="$(dirname -- "`readlink -f -- "$0"`")"
 export PATH="$BASE_DIR/node_modules/.bin":$PATH
 
-# the script can be sourced to update the PATH
-# see https://stackoverflow.com/questions/2683279/how-to-detect-if-a-script-is-being-sourced
-if [ $_ != $0 ]; then
-    unset BASE_DIR
-    # sourced : exit now
-    return
-fi
-
 # subshell
 PYTHONPATH="$BASE_DIR"
 SEARX_DIR="$BASE_DIR/searx"