Filter out None points when calculating RTT

Fix dgzlopes#14

Signed-off-by: Rascal_Two <therealrascaltwo@gmail.com>

Author: RascalTwo

tcp_latency/tcp_latency.py

@@ -86,9 +86,10 @@ def measure_latency(
             if i == len(range(runs))-1:
                 print(f'--- {host} tcp-latency statistics ---')
                 print(f'{i+1} packets transmitted')
-                if latency_points:
+                received_points = [point for point in latency_points if point]
+                if received_points:
                     print(
-                        f'rtt min/avg/max = {min(latency_points)}/{mean(latency_points)}/{max(latency_points)} ms',   # noqa: E501
+                        f'rtt min/avg/max = {min(received_points)}/{mean(received_points)}/{max(received_points)} ms',   # noqa: E501
                     )
 
         latency_points.append(last_latency_point)