local env script stuck if dash/l2config file names not specified

[nkemnitz]

Omitting the config file names (e.g. because Dash or L2Cache is not required, yet) will generate a command like

export DASH_CONFIG=$(cat  | awk '{printf "    %s\n", $0}')

in the local_env_file.sh, which causes cat to silently wait for stdin.

Probably easiest to wrap the file name in quotes - cat "" will complain about the missing file and the script continues with the next line