Use stdin.buffer in get_headers()

We should use stdin.buffer.readline instead of stdin.readline because stdin.read* and stdin.buffer.read* should be used at the same time.  (stdin.read* refers the internal buffer)

python_files/python_server.py

@@ -163,7 +163,7 @@ def get_value(self) -> str:
 def get_headers():
     headers = {}
     while True:
-        line = STDIN.readline().strip()
+        line = STDIN.buffer.readline().decode().strip()
         if not line:
             break
         name, value = line.split(":", 1)