solo.qli: ~Plotfix: Mv hold(h(7), 'on') between irf_plot() calls

MOVE hold(h(7), 'on') to be between two irf_plot() calls.
==> Plot 7's top and right boundaries+ticks come back (previously disappeared).

Plot used to be OK, but has changed without modifying the solo.qli code,
possibly due to updated irf_spectrogram().

modified:   generate_quicklooks_24h_6h_2h.m

mission/solar_orbiter/+solo/+qli/generate_quicklooks_24h_6h_2h.m

@@ -336,10 +336,10 @@ function generate_quicklooks_24h_6h_2h(Data, OutputPaths, Tint24h, logoPath)
 %=====================================
 % Fill panel 7: Vrpw, Vpas velocities
 %=====================================
-hold(h(7), 'on');
 if ~isempty(Data.Vrpw)
   irf_plot(h(7),-Data.Vrpw, 'o-', 'color', COLORS(1,:));
 end
+hold(h(7), 'on');
 if ~isempty(Data.Vpas)
   irf_plot(h(7), Data.Vpas.x.tlim(Tint24h), 'color', COLORS(2,:), 'linewidth', LINE_WIDTH);
 end