Added a warning against using MySQL8

Author: GHMatti

src/server/mysql.js

@@ -22,8 +22,8 @@ class MySQL {
 
     this.pool.query('SELECT VERSION()', (error, result) => {
       if (!error) {
-        const { versionPrefix, version } = formatVersion(result[0]['VERSION()']);
-        profiler.setVersion(`${versionPrefix}:${version}`);
+        const formattedVersion = formatVersion(result[0]['VERSION()']);
+        profiler.setVersion(formattedVersion);
         logger.log('\x1b[32m[mysql-async]\x1b[0m Database server connection established.');
       } else {
         logger.error(`[ERROR] ${error.message}`);

src/server/profiler.js

@@ -52,8 +52,11 @@ class Profiler {
     }
   }
 
-  setVersion(version) {
-    this.version = version;
+  setVersion({ versionPrefix, version }) {
+    if (version.startsWith('8.0.') && versionPrefix === 'MySQL') {
+      this.logger.error('[mysql-async] [Warning] It is recommended to run MySQL 5 or MariaDB with mysql-async. You may experience performance issues under load by using MySQL 8.');
+    }
+    this.version = `${versionPrefix}:${version}`;
   }
 
   fillExecutionTimes(interval) {