Slight discrepancy in number of targets and decoys in `withdecoys.fasta` after mzLib decoy generation

[acesnik]

Probably due to length discrepancies of entries following decoy variant generation in mzLib.

For example:

$ grep -c "^>mz" variants/combined.spritz.snpeff.protein.withdecoys.fasta
90268
$ grep -c "^>rev_mz" variants/combined.spritz.snpeff.protein.withdecoys.fasta
90584

For now, if you want to select targets before searching, do so with grep "^>mz" combined.spritz.snpeff.protein.withdecoys.fasta > combined.spritz.snpeff.protein.justtargets.fasta to produce a file combined.spritz.snpeff.protein.justtargets.fasta.