Fix occurrences of 'have been' to 'has been' (#578)

* Update comments.rs

* Update medias.rs

* Update posts.rs

* Update user.rs

* Update posts.rs

* Update user.rs

src/routes/comments.rs

@@ -94,7 +94,7 @@ pub fn create(
                 Redirect::to(
                     uri!(super::posts::details: blog = blog_name, slug = slug, responding_to = _),
                 ),
-                i18n!(&rockets.intl.catalog, "Your comment have been posted."),
+                i18n!(&rockets.intl.catalog, "Your comment has been posted."),
             )
         })
         .map_err(|errors| {
@@ -169,7 +169,7 @@ pub fn delete(
     }
     Ok(Flash::success(
         Redirect::to(uri!(super::posts::details: blog = blog, slug = slug, responding_to = _)),
-        i18n!(&rockets.intl.catalog, "Your comment have been deleted."),
+        i18n!(&rockets.intl.catalog, "Your comment has been deleted."),
     ))
 }