fix compile

Geo/GFaceCompound.cpp

@@ -2392,6 +2392,7 @@ void GFaceCompound::getTriangle(double u, double v,
 
 void GFaceCompound::buildOct() const
 {
+#if defined(HAVE_MESH)
   SBoundingBox3d bb;
   int count = 0;
   std::list<GFace*>::const_iterator it = _compound.begin();
@@ -2529,6 +2530,7 @@ void GFaceCompound::buildOct() const
   kdtree = new ANNkd_tree(nodes, count, 3);
 
   printStuff();
+#endif
 }
 
 bool GFaceCompound::checkTopology() const