Remove duplicate values in pfcp_pr_time_unit_vals

** (process:8955): WARNING **: Field 'Uplink Time Unit' (pfcp.ul_time_unit) has a conflicting entry in its value_string: 3 is at indices 3 (Day) and 4 (Week))

** (process:8955): WARNING **: Field 'Downlink Time Unit' (pfcp.dl_time_unit) has a conflicting entry in its value_string: 3 is at indices 3 (Day) and 4 (Week))

Change-Id: I870af4a53721e0ffe0f9f778c8287e090f2b2929
Reviewed-on: https://code.wireshark.org/review/23985
Reviewed-by: Michael Mann <mmann78@netscape.net>
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

epan/dissectors/packet-pfcp.c

@@ -2465,7 +2465,7 @@ static const value_string pfcp_pr_time_unit_vals[] = {
     { 1, "6 minutes" },
     { 2, "Hour" },
     { 3, "Day" },
-    { 3, "Week" },
+    { 4, "Week" },
     { 0, NULL }
 };