gluon-web-osm: Fix " rendering in attribution with CDATA tag (#2398)

(cherry picked from commit bbc00017)

package/gluon-web-osm/files/lib/gluon/web/view/model/osm/map.html

 <div id="<%=id%>" class="gluon-osm-map" style="display: none"></div>
 <script type="text/javascript" src="/static/gluon-web-osm.js"></script>
 <script type="text/javascript">
+	//<![CDATA[
 	(function() {
 		var elMap = document.getElementById(<%=json(id)%>);
 		var wrapper = elMap.parentNode;
@@ -41,4 +42,5 @@
 			});
 		});
 	})();
+	//]]>
 </script>