"If you compile the open source software that we make available from time to time to develop your own mobile, desktop or web application, and cause that application to connect to our servers for any purposes, we refer to that resulting application as an 'Open Source App'."
Then, they say the part you quoted, so the gist is that if you elect to use their servers, you have to use them the out-of-the-box way.
But you're not required to use their servers, if you can somehow procure a compatible one. They're not helping you with that, though.
"If you compile the open source software that we make available from time to time to develop your own mobile, desktop or web application, and cause that application to connect to our servers for any purposes, we refer to that resulting application as an 'Open Source App'."
Then, they say the part you quoted, so the gist is that if you elect to use their servers, you have to use them the out-of-the-box way.
But you're not required to use their servers, if you can somehow procure a compatible one. They're not helping you with that, though.