fix issues pointed out by @BaptisteGelez in review

plume-models/src/blogs.rs

@@ -335,7 +335,7 @@ impl Blog {
                 .unwrap_or_else(|| Host::new(format!(
                     "{}/~/{}",
                     Instance::get_local().unwrap().public_domain,
-                    self.title
+                    self.fqn,
                 )))
         )
     }

src/routes/blogs.rs

@@ -68,7 +68,7 @@ pub fn details(
 
     match (blog.custom_domain, page) {
         (Some(ref custom_domain), Some(ref page)) => {
-            Ok(Redirect::to(format!("https://{}/?{}", custom_domain, page)).into())
+            Ok(Redirect::to(format!("https://{}/?page={}", custom_domain, page)).into())
         }
         (Some(ref custom_domain), _) => {
             Ok(Redirect::to(format!("https://{}/", custom_domain)).into())