use correct internal server version

[ChristophWurst]

Otherwise the app installation fails with

occ app:enable mail                                                                                                     

                                                                                                                                 
  [Exception]                                                                                                                    
  App "Mail" cannot be installed because the following dependencies are not fulfilled: Server version 10 or higher is required.  

I suspect PR nextcloud/server#1940 caused this incompatibility. cc @LukasReschke

[LukasReschke]

👍

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and questions.