cosmetic: gbproxy: fix missing closing parenthesis in log line

Change-Id: I4f2b5ef048ccd03d5ac2f448ef14691ece3200d2
diff --git a/gbproxy/GBProxy_Tests.ttcn b/gbproxy/GBProxy_Tests.ttcn
index d32e3bb..ac81580 100644
--- a/gbproxy/GBProxy_Tests.ttcn
+++ b/gbproxy/GBProxy_Tests.ttcn
@@ -1319,7 +1319,7 @@
 		var template (present) PDU_BSSGP pdu_rx :=
 			tr_BSSGP_DL_UD(g_pars.tlli, payload, tr_BSSGP_IMSI(g_pars.imsi));
 
-		log("DL-UNITDATA(payload_size=", i);
+		log("DL-UNITDATA(payload_size=", i, ")");
 		f_sgsn2pcu(pdu_tx, pdu_rx);
 	}
 	setverdict(pass);