Reduce log level when preference and history files not found

src/history.rs

@@ -27,7 +27,7 @@ use std::path::PathBuf;
 use std::sync::RwLock;
 
 use lazy_static::lazy_static;
-use log::{error, warn};
+use log::{info, warn};
 use serde::{Deserialize, Serialize};
 
 static HISTORY_FILE: &str = "rusty-calc-history.json";
@@ -46,7 +46,8 @@ static ref HISTORY_MANAGER: HistoryManager = {
                         serde_json::from_str(&contents).unwrap_or(History::new(HISTORY_SIZE))
                     }
                     Err(e) => {
-                        error!("Unable to open history file: {}", e);
+                        warn!("Unable to open history file: {}", e);
+                        info!("A new history file will be created");
                         History::new(HISTORY_SIZE)
                     }
                 }

src/ui/preferences.rs

@@ -28,7 +28,7 @@ use std::{
 };
 
 use lazy_static::lazy_static;
-use log::error;
+use log::{error, info, warn};
 use preferences::{AppInfo, Preferences, PreferencesMap};
 
 static PREFS_PATH: &str = "rusty-calc.config";
@@ -47,7 +47,8 @@ lazy_static! {
             match PreferencesMap::<String>::load(&APP_INFO, PREFS_PATH) {
                 Ok(map) => Arc::new(RwLock::new(map)),
                 Err(e) => {
-                    error!("Error opening preferences {}", e);
+                    warn!("Error opening preferences {}", e);
+                    info!("A new preferences file will be created");
                     Arc::new(RwLock::new(PreferencesMap::new()))
                 }
             }