Handle removed repository in GitLab

This changes prevents the following fatal error:

  DecodeError ["Unknown GetProjectMergeRequests response: GetProjectMergeRequests {project = Nothing}"]

By properly handling removed project.

Author: TristanCacqueray

src/Lentille/GitLab/MergeRequests.hs

@@ -148,6 +148,12 @@ transformResponse host getIdentIdCB result =
         , NoErr
         , extract shortName fullName <$> catMaybes nodes
         )
+    GetProjectMergeRequests Nothing ->
+      ( PageInfo False Nothing Nothing
+      , Nothing
+      , NoRepo
+      , []
+      )
     _anyOtherResponse ->
       ( PageInfo False Nothing Nothing
       , Nothing