set IS_GECKO to true only for real gecko browsers, not for webkit ones. r=bartvde (closes #2942)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@10909 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Util.js

@@ -1636,7 +1636,8 @@ OpenLayers.Util.removeTail = function(url) {
  * {Boolean} True if the userAgent reports the browser to use the Gecko engine
  */
 OpenLayers.IS_GECKO = (function() {
-    return navigator.userAgent.toLowerCase().indexOf("gecko") != -1;
+    var ua = navigator.userAgent.toLowerCase();
+    return ua.indexOf("webkit") == -1 && ua.indexOf("gecko") != -1;
 })();
 
 /**