Fix incomplete file transfer from COBC to GS

[patrick483]

Description

COPY_A_FILE often fails to properly copy a file from COBC to GS.

The most prominent error case can be reproduced as follows:

1. Flash the FlatSat with firmware version 1.0.0 (you can use FORCE_ENABLE_DEBUG_PRINT=ON)
2. Copy a file with at least some kb from COBC to GS with COPY_A_FILE. Some packets have to get lost.
3. GS realizes packets got lost and sends NAKs. THE COBC does not get the NAKs and terminates the transfer after some time.

What was tried:

1. Increase nakTimerInterval and nakLimit
2. Increase or shorten the time between sending NAKs in Cosmos
3. Change variables related to cfdp stuff in Cosmos

History of problem:

The file transfer worked before. In the meantime no big changes to the firmware were made, except bringing it to the final configuration for launch. For example telemetryThreadInterval was changed from 10s to 30s as well as the corresponding variables in Cosmos. So maybe it's some kind of timing problem.