Update flimesolve.py

Fixed FFTshift issue third time. Needed to flip the FFT'd collapse operators to get decay moving in the proper direction. Now FLiMESolve relaxes to MESolve for both pulsed and CW systems, and it even decays to zero like it should.

qutip/solver/flimesolve.py

@@ -73,9 +73,10 @@ def _floquet_rate_matrix(floquet_basis, Nt, c_ops, time_sense=0):
             c_op.full(),
             modes_table,
         )
-        c_op_Fourier_amplitudes_list = np.fft.fftshift(
-            np.fft.fft(c_op_Floquet_basis, axis=0)
-        ) / len(tlist)
+        c_op_Fourier_amplitudes_list = np.flip(
+            np.fft.fftshift(np.fft.fft(c_op_Floquet_basis, axis=0))
+            / len(tlist)
+        )
 
         # Building the Rate matrix
         delta_m = np.add.outer(-floquet_basis.e_quasi, floquet_basis.e_quasi)