Set params after onSearchStart has been called, closes #561

Author: Tomas Kirda

src/jquery.autocomplete.js

@@ -558,12 +558,13 @@
                 ajaxSettings;
 
             options.params[options.paramName] = q;
-            params = options.ignoreParams ? null : options.params;
 
             if (options.onSearchStart.call(that.element, options.params) === false) {
                 return;
             }
 
+            params = options.ignoreParams ? null : options.params;
+
             if ($.isFunction(options.lookup)){
                 options.lookup(q, function (data) {
                     that.suggestions = data.suggestions;