Make the ExcelTable 'Address' settable to allow expansion of Excel table on insert at end of the Excel table.

EPPlus/Table/ExcelTable.cs

diff --git a/EPPlus/Table/ExcelTable.cs b/EPPlus/Table/ExcelTable.cs
index 0f3901b..1d58a01 100644
--- a/EPPlus/Table/ExcelTable.cs
+++ b/EPPlus/Table/ExcelTable.cs
@@ -278,7 +278,7 @@
             {
                 return _address;
             }
-            internal set
+            set
             {
                 _address = value;
                 SetXmlNodeString("@ref",value.Address);