Update serialVersionUID in ImportedTableInfo since a new field was added (apache#4215)

Author: DomGarguilo

server/manager/src/main/java/org/apache/accumulo/manager/tableOps/tableImport/ImportedTableInfo.java

@@ -26,7 +26,7 @@
 
 class ImportedTableInfo implements Serializable {
 
-  private static final long serialVersionUID = 1L;
+  private static final long serialVersionUID = 2L;
 
   public String user;
   public String tableName;