docs: fix broken link to vlib/net/socket.v

doc/docs.md

@@ -3281,7 +3281,7 @@ To cast a `voidptr` to a V reference, use `user := &User(user_void_ptr)`.
 
 `voidptr` can also be dereferenced into a V struct through casting: `user := User(user_void_ptr)`.
 
-[socket.v has an example which calls C code from V](https://github.com/vlang/v/blob/master/vlib/net/socket.v) .
+[an example of a module that calls C code from V](https://github.com/vlang/v/blob/master/vlib/v/tests/project_with_c_code/mod1/wrapper.v)
 
 ## Debugging generated C code