Revert "[3.7] bpo-34589: Add -X coerce_c_locale option; C locale coercion off by default (GH-9379)" (GH-9416)

This reverts commit 144f1e2c6f4a24bd288c045986842c65cc289684.
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ef742c1..ba4b548 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -400,7 +400,7 @@
 static void
 _emit_stderr_warning_for_legacy_locale(const _PyCoreConfig *core_config)
 {
-    if (core_config->_coerce_c_locale_warn) {
+    if (core_config->coerce_c_locale_warn) {
         if (_Py_LegacyLocaleDetected()) {
             fprintf(stderr, "%s", _C_LOCALE_WARNING);
         }
@@ -462,7 +462,7 @@
                 "Error setting LC_CTYPE, skipping C locale coercion\n");
         return;
     }
-    if (config->_coerce_c_locale_warn) {
+    if (config->coerce_c_locale_warn) {
         fprintf(stderr, C_LOCALE_COERCION_WARNING, newloc);
     }