cmAlgorithms: Remove sort of already-sorted container.

The indices is populated by an increasing number.

Source/cmAlgorithms.h

@@ -275,7 +275,6 @@ typename Range::const_iterator cmRemoveDuplicates(Range& r)
     {
     return r.end();
     }
-  std::sort(indices.begin(), indices.end());
   return cmRemoveIndices(r, indices);
 }