disabled unused macro declaration that was causing conflict

[RootDmytro]

disabled SPIFFS redeclaration that was creating declaration conflict as a byproduct in sources that would include JPEGDecoder.h This was the cause of error: JPEGDecoder.h:48:20: error: conflicting declaration 'fs::SPIFFSFS LittleFS' whenever JPEGDecoder.h was included before inclusion of SPIFFS-related headers, such as TFT_eSPI.h.