Merge hashrate and difficulty into one chart

backend/src/repositories/BlocksRepository.ts

@@ -187,12 +187,11 @@ class BlocksRepository {
    * Get the oldest indexed block
    */
   public async $oldestBlockTimestamp(): Promise<number> {
-    const query = `SELECT blockTimestamp
+    const query = `SELECT UNIX_TIMESTAMP(blockTimestamp) as blockTimestamp
       FROM blocks
       ORDER BY height
       LIMIT 1;`;
 
-
     // logger.debug(query);
     const connection = await DB.pool.getConnection();
     const [rows]: any[] = await connection.query(query);