ferdium-server uses same sentry instance as getferdi/ferdi

[lukasmichel]

As for ferdium-app (ferdium/ferdium-app#233), ferdium-server uses the same sentry instance as getferdi/server. (Compare the files https://github.com/ferdium/ferdium-server/blob/08de0c4237916a2e5a4aa855b1474ab8b00e67ac/server.js and https://github.com/getferdi/server/blob/343fc8ca133584a3da784ae43452b680a1899b68/server.js).

As for ferdium-app (see ferdium/ferdium-app#234), the sentry integration should probably be removed for now.