Remove unused writePool function

src/network.ts

@@ -195,10 +195,6 @@ function readPool(): IpPool {
   }
 }
 
-function writePool(pool: IpPool) {
-  writeFileSync(CONFIG.ipPoolFile, JSON.stringify(pool));
-}
-
 function atomicWritePool(pool: IpPool) {
   const tmp = CONFIG.ipPoolFile + ".tmp";
   writeFileSync(tmp, JSON.stringify(pool));