fix mysql date converstion (#8630)

HaxeFoundation/hashlink#279

std/hl/_std/sys/db/Mysql.hx

@@ -231,7 +231,7 @@ class Mysql {
 		if (!INIT_DONE) {
 			INIT_DONE = true;
 			MysqlConnection.setConvFuns(function(v:hl.Bytes) return @:privateAccess String.fromUTF8(v),
-			function(v:hl.Bytes, len:Int) return new haxe.io.Bytes(v, len), function(t) return Date.fromTime(t),
+			function(v:hl.Bytes, len:Int) return new haxe.io.Bytes(v, len), function(t) return Date.fromTime(1000. * t),
 			function(v:hl.Bytes) return haxe.Json.parse(@:privateAccess String.fromUTF8(v)));
 		}
 		var p = new MysqlParams();