message: refine NI comment
diff: @@ -153,7 +153,8 @@ public:
  /// Enable partial assembly for every operator.
  void EnablePA(bool pa) { partial_assembly = pa; }
  - /// Enable numerical integration rules.
  + /// Enable numerical integration rules. This means collocated quadrature at
  + /// the nodal points.
  void EnableNI(bool ni) { numerical_integ = ni; }
  /// Print timing summary of the solving routine.
  