MXS-2188: Update target table in prepare_table

Passing the target table and create to the prepare_table function allows
the converter to update the internal variables.

server/modules/routing/avrorouter/rpl.hh

@@ -183,8 +183,8 @@ public:
         return true;
     }
 
-    // Prepare a new row for processing
-    virtual bool prepare_table(std::string database, std::string table)
+    // Prepare a table for row processing
+    virtual bool prepare_table(const STableMapEvent& map, const STableCreateEvent& create)
     {
         return true;
     }