Get rid of empty processes

[LouisLeNezet]

Description of feature

The log is fill up with the processes populated after a branching event even if nothing is present in the branch.
It would be nice to have a if statement to not show the processes if no input is present in the branch.

[-        ] NFCORE_PHASEIMPUTE:CHRCHECK_INPUT:VCF_CHR_EXTRACT                               -
[00/8502fd] NFCORE_PHASEIMPUTE:CHRCHECK_INPUT:BAM_CHR_EXTRACT (NA20359)                     [100%] 3 of 3 ✔
[-        ] NFCORE_PHASEIMPUTE:CHRCHECK_TRUTH:VCF_CHR_EXTRACT                               -
[-        ] NFCORE_PHASEIMPUTE:CHRCHECK_TRUTH:BAM_CHR_EXTRACT                               -
[05/b842ad] NFCORE_PHASEIMPUTE:CHRCHECK_PANEL:VCF_CHR_EXTRACT (1000GP chr21)                [100%] 2 of 2 ✔
[-        ] NFCORE_PHASEIMPUTE:CHRCHECK_PANEL:BAM_CHR_EXTRACT                               -
[21/1007bf] NFCORE_PHASEIMPUTE:PHASEIMPUTE:LIST_TO_FILE (all)                               [100%] 1 of 1 ✔
[5c/c5ffe2] NFCORE_PHASEIMPUTE:PHASEIMPUTE:GL_GLIMPSE1:GAWK (1000GP chr22)                  [100%] 2 of 2 ✔
[44/8d9f5a] NFCORE_PHASEIMPUTE:PHASEIMPUTE:GL_GLIMPSE1:TABIX_BGZIP (1000GP chr21)           [100%] 2 of 2 ✔
[02/3998e3] NFCORE_PHASEIMPUTE:PHASEIMPUTE:GL_GLIMPSE1:BCFTOOLS_MPILEUP (NA20359 chr22)     [100%] 6 of 6 ✔