Remove `Terminated` message on 22.04

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index fdbb310..53b3885 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1362,7 +1362,7 @@
 
     if [ -n "$PXY_CMD" ]; then
         kill $PXY_PID >/dev/null 2>&1
-        wait $PXY_PID
+        wait $PXY_PID >> $PXY_OUT 2>&1
     fi
 }