The config execution.attached doesn't take effect when not set by Cli param

The config execution.attached's default value is false. But no matter what value we set, it takes no effect. After digging in, we find that it is only affected by Cli param as following:

1. If we don't specify -d or -yd, the member detachedMode in ProgramOptions is set to false.
2. In method applyToConfiguration, the execution.attached is set true.
3. No matter what value is set to execution.attached, it take no effect.

If -d or -yd is not set, we should use the config execution.attached. Since the actual attach mode is using for a long time, we may need to change execution.attached's default value to true after the modification.