Fix wrong props name in txtime

scripts/txtime_stats.py

@@ -34,7 +34,7 @@ def compute_offsets_stats(file_path, interval):
 
     measure_set = {}
     measure_set["measure_type"] = "packet_jitter_tcpdump"
-    measure_set["props_names"] = ["packet_jitter_tcpdump"]
+    measure_set["props_names"] = ["jitter"]
     measure_set["units"] = ["us"]
     measure_set["props_type"] = "histogram"
     measure_set["metadata"] = {"i": interval}