network-weathermap: Cacti Plugin is creating duplicate records in plugin_realms

Hey @howardjones,

For some reason, your plugin is creating many plugin_realm entries. I am not sure if this is a bug with the cacti realm code or your method of creating the realm but if you select the plugini_realm table, it has a few copies of your plugin within it.

select * from plugin_realms

As per https://github.com/Cacti/cacti/issues/1388