[upsert] Fix NPE in case of non empty database name (#644)

Signed-off-by: Enrico Olivelli <eolivelli@gmail.com>

src/main/java/io/milvus/param/ParamUtils.java

@@ -265,7 +265,7 @@ public class ParamUtils {
                     .setBase(msgBase)
                     .setNumRows(requestParam.getRowCount());
             if (StringUtils.isNotEmpty(requestParam.getDatabaseName())) {
-                insertBuilder.setDbName(requestParam.getDatabaseName());
+                upsertBuilder.setDbName(requestParam.getDatabaseName());
             }
             fillFieldsData(requestParam, wrapper);
         }