[FIX] Fix CS50 link in CS61A (#654)

docs/编程入门/Python/CS61A.en.md

@@ -20,7 +20,7 @@ CS61B and CS61C are both included in this guidebook.
 
 Going back to CS61A, you will note that this is not just a programming language class, but goes deeper into the principles of program construction and operation. Finally you will implement an interpreter for Scheme in Python in Project 4. In addition, abstraction will be a major theme in this class, as you will learn about functional programming, data abstraction, object orientation, etc. to make your code more readable and modular. Of course, learning a programming language is also a big part of this course. You will master three programming languages, Python, Scheme, and SQL, and in learning and comparing them, you will be equiped with the ability to quickly master a new programming language.
 
-Note: If you have no prior programming experience at all, getting started with CS61A requires a relatively high level of learning ability and self-discipline. To avoid the frustration of a struggling experience, you may choose a more friendly introductory programming course at first. For example, [CS10](https://cs10.org/sp22/) at Berkeley or [CS50](https://csdiy.wiki/编程入门/CS50/) at Harvard are both good choices.
+Note: If you have no prior programming experience at all, getting started with CS61A requires a relatively high level of learning ability and self-discipline. To avoid the frustration of a struggling experience, you may choose a more friendly introductory programming course at first. For example, [CS10](https://cs10.org/sp22/) at Berkeley or [CS50](https://csdiy.wiki/编程入门/C/CS50/) at Harvard are both good choices.
 
 ## Course Resources