fixed mani.jsfg

psGrammar/tasks/manipulation/manipulationTask.jsgf

 #JSGF V1.0;
 grammar manipulationTask;
 
-public <navigation> = tobi [please] <cleanShelf> | <table>;
+public <navigation> = tobi [please] (<cleanShelf> | <table>);
 <cleanShelf> = clean the shelf;
 <table> = clean the table;