fixed add_seq for setting mask exons to off
fixed add_seq for setting mask exons to off

LyonsLab/coge,LyonsLab/coge,asherkhb/coge,asherkhb/coge,asherkhb/coge,asherkhb/coge,LyonsLab/coge,asherkhb/coge,asherkhb/coge,LyonsLab/coge,LyonsLab/coge,asherkhb/coge,LyonsLab/coge,LyonsLab/coge,LyonsLab/coge,LyonsLab/coge,asherkhb/coge,asherkhb/coge