latencyTestTargets fix

query-node/mappings/storage/metadata.ts

@@ -135,7 +135,7 @@ export async function processDistributionBucketFamilyMetadata(
     metadataEntity.description = meta.description || (null as any)
   }
   if (isSet(meta.latencyTestTargets)) {
-    metadataEntity.latencyTestTargets = meta.latencyTestTargets
+    metadataEntity.latencyTestTargets = meta.latencyTestTargets.filter((t) => t)
   }
 
   await store.save<DistributionBucketOperatorMetadata>(metadataEntity)

query-node/schemas/storage.graphql

@@ -230,7 +230,7 @@ type DistributionBucketFamilyMetadata @entity {
   areas: [DistributionBucketFamilyGeographicArea!] @derivedFrom(field: "distributionBucketFamilyMetadata")
 
   "List of targets (hosts/ips) best suited latency measurements for the family"
-  latencyTestTargets: [String!]
+  latencyTestTargets: [String]
 }
 
 type DistributionBucketOperatorMetadata @entity {