json-c from network project

For 15.6 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/network/15.6/network.repo
zypper refresh
zypper install json-c

For 15.5 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/network/15.5/network.repo
zypper refresh
zypper install json-c

For SLE 15 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/network/SLE_15/network.repo
zypper refresh
zypper install json-c