Mouse IG Reference Sets Updated

Fixes have been made to two mouse reference sets. In C57BL/6 IGH, a stray character in the coding sequence for IGHV-KAOG has been removed. There are no other changes to this set. In PWD/PhJ IGH, the delineation j_cdr3_end has been corrected. There are no other changes in this set, and coding sequences are unchanged.