Bugfix, plot ack_rtt

plot_transmission_timeline.py

     plt.subplots_adjust()
 
     host.plot(transmission_df["goodput"], "-", color="blue", label="goodput")
-    #host.set_xlabel("datetime")
-    #host.set_ylabel("goodput [Mbps]")
+    host.set_xlabel("datetime")
+    host.set_ylabel("goodput [Mbps]")
 
     # additional y axes
     par11 = host.twinx()