Fix `OsuGameBase.Migrate()` eating exception messages for breakfast

Whomst've thought this was an ok thing to do? How did this pass review?
Let's leave these as rhetorical questions right now. Huge chances are
I'd implicate myself with at least one of them.

osu.Game/OsuGameBase.cs

@@ -545,7 +545,10 @@ public bool Migrate(string path)
                         realmBlocker = realm.BlockAllOperations("migration");
                         success = true;
                     }
-                    catch { }
+                    catch (Exception ex)
+                    {
+                        Logger.Log($"Attempting to block all operations failed: {ex}", LoggingTarget.Database);
+                    }
 
                     readyToRun.Set();
                 }, false);