Remove tripled up survey legs in loser/caves/264/hiltigalactica.svx

[goatchurchprime]

This has sections in the data like:

     15        16      4.376  325.91   24.71  [1]    
     15        16      4.363  326.04   24.91  [1]    
     15        16      4.370  325.77   25.00  [1]    
     16        -          0.922  209.03   74.04  [1]    
     16        -          0.360   60.51   29.58  [1]    
     16        -          0.583  193.31    4.26  [1]    
     16        -          0.275  178.71  -80.30  [1]    
     16        17      2.063  220.48   31.42  [1]    
     16        17      2.067  219.96   31.33  [1]    
     16        17      2.067  219.83   31.34  [1]    
     2         -          0.000    0.00    0.00  [1]    
     2         18      9.038   39.63    4.08  [1]    
     2         18      9.047   39.62    3.97  [1]    
     2         18      9.019   39.64    4.11  [1]    

It's probably created by the pockettopo system with the raw shots left in. It would be better to replace these by the averaged numbers rather than leave in this tripled up form in the original data as it's a very rare convention which appears like a bug when you are trying to do stuff with the survey legs using another applications.