Crash when importing invalid module on REPL

Describe the bug

Related #176

Invalid import causes multiple error messages and then crashes on any input.

Reproducible code

>>> import "a"
Traceback (most recent call last):
  File "<string>", line 28, in <module>
  File "<string>", line 1, in <module>
  File "<stdin>", line -1, in <module>
ModuleNotFoundError: No module named 'a'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 32, in <module>
NameError: name 'e' is not defined

>>>
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 10053, kind: ConnectionAborted, message: "確立された接続がホスト コンピューターのソウトウェアによって中止されました。" }', src\dummy.rs:77:49
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Any { .. }', src\main.rs:63:22    
error: process didn't exit successfully: `target\debug\erg.exe` (exit code: 101)

Expected behavior

Error message and don't crash

Additional context

The following code is crashing at stream.write_all("exit".as_bytes()).unwrap();

If it fails to read, it seems to fail to write as well

https://github.com/erg-lang/erg/blob/f6e1a7b11783d7f4c78f4e1e1ba6cda048747fc8/src/dummy.rs#L75-L78

erg-lang / erg

Crash when importing invalid module on REPL #179