make Http[s]ListenerConfig::http_answers optional

command/src/command.proto

@@ -129,7 +129,7 @@ message HttpListenerConfig {
     required uint32 request_timeout = 10 [default = 10];
     // wether the listener is actively listening on its socket
     required bool active = 11 [default = false];
-    required CustomHttpAnswers http_answers = 12;
+    optional CustomHttpAnswers http_answers = 12;
 }
 
 // details of an HTTPS listener
@@ -161,7 +161,7 @@ message HttpsListenerConfig {
     // The tickets allow the client to resume a session. This protects the client
     // agains session tracking. Defaults to 4.
     required uint64 send_tls13_tickets = 20;
-    required CustomHttpAnswers http_answers = 21;
+    optional CustomHttpAnswers http_answers = 21;
 }
 
 // details of an TCP listener

command/src/config.rs

@@ -427,7 +427,7 @@ impl ListenerBuilder {
     }
 
     /// Get the custom HTTP answers from the file system using the provided paths
-    fn get_http_answers(&self) -> Result<CustomHttpAnswers, ConfigError> {
+    fn get_http_answers(&self) -> Result<Option<CustomHttpAnswers>, ConfigError> {
         let http_answers = CustomHttpAnswers {
             answer_301: read_http_answer_file(&self.answer_301)?,
             answer_400: read_http_answer_file(&self.answer_400)?,
@@ -440,7 +440,7 @@ impl ListenerBuilder {
             answer_504: read_http_answer_file(&self.answer_504)?,
             answer_507: read_http_answer_file(&self.answer_507)?,
         };
-        Ok(http_answers)
+        Ok(Some(http_answers))
     }
 
     /// Assign the timeouts of the config to this listener, only if timeouts did not exist

command/src/logging/logs.rs

@@ -1,7 +1,6 @@
 use std::{
     cell::RefCell,
-    cmp,
-    env,
+    cmp, env,
     fmt::Arguments,
     fs::{File, OpenOptions},
     io::{stdout, Error as IoError, ErrorKind as IoErrorKind, Stdout, Write},