Update set_fact.sh to support multiple network

[quivalen]

Currently the role will fail to regather fact if there is more than 1 zerotier network configured

NETWORKS=$(zerotier-cli listnetworks | tail -n+2) will rightly contain the data with \n

But without the quotes echo will suppress the \n writing everything in one line.
Thus wc -l will return 1, confusing the file_content function that will lead to an incorrect json being produced

How to reproduce?
Without the fix, try to setup a second zerotier network - You will see that the regather fact step will fail, leading to no authorization of the node (as it cannot get the right fact)
If you inspect /etc/ansible/facts.d/zerotier.fact you will see that the json is malformed, the first network will fulfill

ansible-role-zerotier/files/set_facts.sh

Line 21 in c7aae63

if [ "$counter" -eq "$network_count" ]; then

while all the others will match

ansible-role-zerotier/files/set_facts.sh

Line 23 in c7aae63

else

[m4rcu5nl]

Nice catch. Thanks!