chore(src/main.rs): fix typo (#534)

hi, awesome project, thank you!

just noticed a typo, doesn't break any tests.

Author: replydev

src/main.rs

@@ -74,7 +74,7 @@ fn main() -> AppResult<()> {
 
     let error_code = if reowned_database.is_modified() {
         if let Ok(()) = reowned_database.save(&key, &salt) {
-            println!("Modifications has been persisted");
+            println!("Modifications have been persisted");
             0
         } else {
             eprintln!("An error occurred during database overwriting");