Fix the `stop` error when no `milvus` process (#20101)

Signed-off-by: NSimFG <bang.fu@zilliz.com>
Signed-off-by: NSimFG <bang.fu@zilliz.com>

scripts/stop.sh

@@ -16,6 +16,10 @@
 
 echo "Stopping milvus..."
 PROCESS=$(ps -e | grep milvus | grep -v grep | awk '{print $1}')
+if [ -z "$PROCESS" ]; then
+  echo "No milvus process"
+  exit 0
+fi
 kill -9 $PROCESS
 echo "Milvus stopped"