[LPD] [Correct] Fix mistakes in parallel-gain non-combining mode

My mistake. I'm running this now and the code has already passed the point it failed before.

@hammerd @schmidtp

notebooks/LPD/LPD_Correct_Fast.ipynb

             # Replicate corrected cell and pulse IDs from high gain to other gains.
             tmp_cell = np.zeros_like(in_cell)
             tmp_pulse = np.zeros_like(in_pulse)
-            sel = np.zeros_like(in_cell)
+            sel = np.zeros_like(in_cell, dtype=np.bool_)
 
             cursor_in = cursor_out = 0
             for afc in actual_frame_counts:
                     sel[cursor_out : cursor_out+afc] = 1
                     cursor_out += afc + drop_last_frames_parallelgain
 
-                cursor_in += afc + drop_last_frames_parallelgain
+                cursor_in += 3 * (afc + drop_last_frames_parallelgain)
 
             # Apply the selection to drop trailing frames
             in_cell = tmp_cell[sel]