fix error in rnd

[leonard-q]

:star2: Hello! Thanks for contributing JORLDY!

Checklist

Please check if you consider the following items.

• [V] My code follows the style guidelines of this project contributing
• [V] My code follows the naming convention of documentation
• [V] I have commented my code, particularly in hard-to-understand areas
• [V] My changes generate no new warnings or errors

Types of changes

Please describe the types of changes! (ex. Bugfix, New feature, Documentation, ...) Bug fix

Test Configuration

• OS: Linux Ubuntu
• Python version: 3.8
• Additional libraries: None

Description

Please describe the details of your contribution

Bug was occurred after RND refactoring. The target network parameters have to contain "target" in their name, but it changed to 't', so RND target network also trained for minimizing r_i. This commit fixed this problem