Update 'nuclear-power-plants.json'

Correct expression according to https://taginfo.openstreetmap.org/tags/plant%3Asource=nuclear > https://overpass-turbo.eu/ :

(node["plant:source"="nuclear"];
way["plant:source"="nuclear"];
relation["plant:source"="nuclear"];)

nuclear-power-plants.json

@@ -6,6 +6,10 @@
         "fr": "Centrales nucléaires"
     },
     "query": {
-        "7": "way[power:source=nuclear];"
+        "7": [
+            "(node[\"plant:source\"=\"nuclear\"];",
+            "way[\"plant:source\"=\"nuclear\"];",
+            "relation[\"plant:source\"=\"nuclear\"];)"
+        ]
     }
 }