Don't prefetch more frequently than 1/min

dnscrypt-proxy/main.go

@@ -194,7 +194,7 @@ func (proxy *Proxy) prefetcher(urlsToPrefetch *[]URLToPrefetch) {
 					}
 				}
 			}
-			time.Sleep(5 * time.Second)
+			time.Sleep(60 * time.Second)
 		}
 	}()
 }