added BlockParser dtor

include/maddy/blockparser.h

@@ -45,6 +45,13 @@ public:
     , getBlockParserForLineCallback(getBlockParserForLineCallback)
   {}
 
+  /**
+   * dtor
+   *
+   * @method
+   */
+  virtual ~BlockParser() {}
+
   /**
    * AddLine
    *