Handle missing allow_auto_merge attribute on repositories

It can be missing if the repository is archived.

Author: Kobzol

src/github/api/mod.rs

@@ -258,7 +258,8 @@ pub(crate) struct Repo {
     pub(crate) description: Option<String>,
     pub(crate) homepage: Option<String>,
     pub(crate) archived: bool,
-    pub(crate) allow_auto_merge: bool,
+    #[serde(default)]
+    pub(crate) allow_auto_merge: Option<bool>,
 }
 
 fn repo_owner<'de, D>(deserializer: D) -> Result<String, D::Error>

src/github/api/write.rs

@@ -236,7 +236,7 @@ impl GitHubWrite {
                 description: settings.description.clone(),
                 homepage: settings.homepage.clone(),
                 archived: false,
-                allow_auto_merge: settings.auto_merge_enabled,
+                allow_auto_merge: Some(settings.auto_merge_enabled),
             })
         } else {
             Ok(self

src/github/mod.rs

@@ -261,7 +261,7 @@ impl SyncGitHub {
             description: actual_repo.description.clone(),
             homepage: actual_repo.homepage.clone(),
             archived: actual_repo.archived,
-            auto_merge_enabled: actual_repo.allow_auto_merge,
+            auto_merge_enabled: actual_repo.allow_auto_merge.unwrap_or(false),
         };
         let new_settings = RepoSettings {
             description: Some(expected_repo.description.clone()),