Fix plot() task in FairseqHydraTrainingJob

[AndreasPlt]

Currently, the task plot() in the FairseqHydraTrainingJob fails (as noted by @vieting off-line) due to an incorrect parsing of the hydra log file. I therefore corrected the parsing of this file to read the loss and LR values from the right lines.

[vieting]

@Judyxujj did you also have failing plot tasks? It does fail for the logs of wav2vec 2.0 pre-training. However, I'm not familiar enough with different fairseq setups to know whether this proposed change will break the task for the logs of other trainings.

[vieting]

@michelwi can you tell why the AppTek hashes test fails? It can hardly be related to the proposed changes here, right?

[michelwi]

@michelwi can you tell why the AppTek hashes test fails? It can hardly be related to the proposed changes here, right?

This is a fork of i6_core and not a branch, therefore it does not have access to our API key to trigger the pipeline and this step immediately fails.

[vieting]

This is a fork of i6_core and not a branch, therefore it does not have access to our API key to trigger the pipeline and this step immediately fails.

I see, thanks. Then we can just ignore this, changes inside the plot task can anyway never affect the hashes.

[vieting]

@Judyxujj could you please have a look at this PR? :)