outbounds: remove unused nil check for GetDefaultHandler (#2457)

Signed-off-by: Seena Fallah <seenafallah@gmail.com>

app/proxyman/outbound/outbound.go

@@ -82,9 +82,6 @@ func (m *Manager) GetDefaultHandler() outbound.Handler {
 	m.access.RLock()
 	defer m.access.RUnlock()
 
-	if m.defaultHandler == nil {
-		return nil
-	}
 	return m.defaultHandler
 }