Parsing mouse ensembl gtf into gene-level data gives duplicate symbols

[lianos]

My parsing of the mouse ensembl gtf into gene-level data gives feature file assigns "Olfr912" and "Srp54a" to more than one ensembl identifier.

For instance, Olfr912 gets assigned to ENSMUSG00000111448 (correctly) but also ENSMUSG00000060114 (incorrectly). The latter should be Olfr910. The archs4 "gene_name" gets this right, so this is now being used for the "symbol" column in commit a34e466