greet rework should be finished. Fixed postgres, removed mysql

src/EllieBot/Db/EllieContext.cs

@@ -690,6 +690,17 @@ public abstract class EllieContext : DbContext
             })
             .IsUnique());
 
+        modelBuilder.Entity<GreetSettings>(gs =>
+        {
+            gs
+                .Property(x => x.IsEnabled)
+                .HasDefaultValue(false);
+
+            gs
+                .Property(x => x.AutoDeleteTimer)
+                .HasDefaultValue(0);
+        });
+
         #endregion
     }