Update a comment

Author: warsaw

Lib/test/libregrtest/save_env.py

@@ -9,7 +9,7 @@
 
 from .utils import print_warning
 
-# Import termios to save and restore the tty.  This is only available on
+# Import termios to save and restore terminal echo.  This is only available on
 # Unix, and it's fine if the module can't be found.
 try:
     import termios