Issue #1677: Unused variable warning in Non-Windows

Author: jcea

Parser/myreadline.c

@@ -36,8 +36,11 @@ static int
 my_fgets(char *buf, int len, FILE *fp)
 {
     char *p;
-    int i;
     int err;
+#ifdef MS_WINDOWS
+    int i;
+#endif
+
     while (1) {
         if (PyOS_InputHook != NULL)
             (void)(PyOS_InputHook)();