[FA-9] Postgres backing works

FictionArchive.Service.SchedulerService/GraphQL/Mutation.cs

@@ -27,7 +27,7 @@ public class Mutation
         bool deleted = await jobManager.DeleteJob(jobKey);
         if (!deleted)
         {
-            throw new KeyNotFoundException($"Job with key {jobKey} was not found");
+            throw new KeyNotFoundException($"Job with key '{jobKey}' was not found");
         }
 
         return true;