isoform_ranking.py shouldn't return an error with a bam with a .csi index

Hello,

I'm testing ingenannot with a >3.5 Gb genomes and isoform_ranking return:

ERROR:root:Problem conf, Missing index (.bai) of bam file

There is an index and it's a .csi as .bai can't be generated on large genomes.

I tried to comment the raise exception (line 392) and it seems to work properly.

Best,

Jonathan