tomtom query edge case in fetch_tomtom_matches

[mhfzsharmin]

@suragnair not all the query get at least $n number of motif matches. You can include the condition that if the next element in dat variable is empty to breaks the loop.

    r = []
    for t in dat[1:1+n]:
        if(len(t)<4):
            break
        mtf = {}
        mtf['Target ID'] = t[tget_idx]
        mtf['p-value'] = float(t[pval_idx])
        mtf['E-value'] = float(t[eval_idx])
        mtf['q-value'] = float(t[qval_idx])
        r.append(mtf)