fix: don't allow to configure fallback or cache with nil Redis|S3 ins… (

#155)

fix: don't allow to configure fallback or cache with nil Redis|S3 instances

server/load_store.go

@@ -23,9 +23,15 @@ func populateTargets(targets []string, s3 store.PrecomputedKeyStore, redis *redi
 
 		switch b {
 		case store.RedisBackendType:
+			if redis == nil {
+				panic(fmt.Sprintf("Redis backend is not configured but specified in targets: %s", f))
+			}
 			stores[i] = redis
 
 		case store.S3BackendType:
+			if s3 == nil {
+				panic(fmt.Sprintf("S3 backend is not configured but specified in targets: %s", f))
+			}
 			stores[i] = s3
 
 		case store.EigenDABackendType, store.MemoryBackendType: