In order to use -n, the value needs either be quoted or [[ .. ]] block
has to be used. Fix the comparisons that way.
To verify, consider this (analogous) script:
#!/bin/bash
subnetwork_url=""
if [ -n ${subnetwork_url} ]; then
echo "foo"
fi
if [[ -n ${subnetwork_url} ]]; then
echo "bar"
fi
Here "foo" is echoed by the script, even though the variable
subnetwork_url has a zero-length value.
