Fix readline.c compiler warning. (GH-98738)

```
Modules/readline.c:1260:37: warning: assigning to 'char *' from 'const char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
    completer_word_break_characters =
                                    ^
```
(cherry picked from commit 29b391b1378577825a658b14764a8ff3e0b5c958)

Co-authored-by: Benjamin Peterson <benjamin@python.org>

diff --git a/Modules/readline.c b/Modules/readline.c
index c79d22f85f84ea3b1b4a5809cf1dc7dcf72168b7..1d5067209072b625ecd20a1f6f47d0f6d7a29d7c 100644 (file)
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -1256,9 +1256,9 @@ setup_readline(readlinestate *mod_state)
     rl_attempted_completion_function = flex_complete;
     /* Set Python word break characters */
     completer_word_break_characters =
-        rl_completer_word_break_characters =
         strdup(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?");
         /* All nonalphanums except '.' */
+    rl_completer_word_break_characters = completer_word_break_characters;
 
     mod_state->begidx = PyLong_FromLong(0L);
     mod_state->endidx = PyLong_FromLong(0L);