Update graticule.js - fixed typo/build error

Corrected reference to variable frameState - it was misspelled by the previous commit.

src/ol/graticule.js

@@ -356,7 +356,7 @@ ol.Graticule.prototype.getParallels = function() {
 ol.Graticule.prototype.handlePostCompose_ = function(e) {
   var vectorContext = e.vectorContext;
   var frameState = e.frameState;
-  var extent = framteState.extent;
+  var extent = frameState.extent;
   var viewState = frameState.viewState;
   var center = viewState.center;
   var projection = viewState.projection;