Fix import

src/mol-model/structure/structure/unit/bonds/inter-compute.ts

@@ -20,7 +20,6 @@ import { InterUnitGraph } from '../../../../../mol-math/graph/inter-unit-graph';
 import { StructConn } from '../../../../../mol-model-formats/structure/property/bonds/struct_conn';
 import { equalEps } from '../../../../../mol-math/linear-algebra/3d/common';
 import { Model } from '../../../model';
-import { StructureProperties } from '../../properties';
 
 // avoiding namespace lookup improved performance in Chrome (Aug 2020)
 const v3distance = Vec3.distance;