TUNE TPS2; b) Don't recompute Q in loop

+ it's already computed in self._StepPrepareWithoutTaskManager()
+ it's time independent

integrators/tps2.py

@@ -234,7 +234,6 @@ class TPS2(_tpsx.TPSX, \
       self._Assemble_f_iter()
       f = self._f_fix.vec.FV().NumPy() + self._f_iter.vec.FV().NumPy()
 
-      self._Compute_Q()
       LHS = self._Q.dot( A.dot( self._Q.transpose() ) ) 
       RHS = self._Q.dot( f )