Revert "Add POST method of /PivotVariables"

This reverts commit 079aa59.

Author: jakcpto

MDX2JSON/REST.cls

@@ -71,7 +71,6 @@ XData UrlMap
 
    <!-- Get info about pivot variables-->
    <Route Url="/PivotVariables/:Cube" Method="GET" Call="WritePivotVariablesForCube"/>
-   <Route Url="/PivotVariables" Method="POST" Call="WritePivotVariablesForCube"/>
 
    <!-- Get info about user config-->
    <Route Url="/Config" Method="POST" Call="SetConfig"/>