[dqt] fix loading saved query (#8436)

Reverting the code back to what it was when it was introduced as the 'keys' parameter in the query string wasn't changed back.

modules/dqt/jsx/react.app.js

@@ -682,23 +682,23 @@ class DataQueryApp extends Component {
       alertSaved: false,
       loading: false,
     });
-    for (let i = 0; i < fieldsList.length; i++) {
-      $.ajax({
-        url: loris.BaseURL + '/dqt/ajax/datadictionary.php',
-        success: (data) => {
-          if (data[0] && data[0].value.IsFile) {
-            let key = data[0].key[0] + ',' + data[0].key[1];
+    $.ajax({
+      url: loris.BaseURL + '/dqt/ajax/datadictionary.php',
+      success: (data) => {
+        for (let i = 0; i < fieldsList.length; i++) {
+          if (data[i] && data[i].value.IsFile) {
+            let key = data[i].key[0] + ',' + data[i].key[1];
             let downloadable = this.state.downloadableFields;
             downloadable[key] = true;
             this.setState({
               downloadableFields: downloadable,
             });
           }
-        },
-        data: {key: fieldsList[i]},
-        dataType: 'json',
-      });
-    }
+        }
+      },
+      data: {keys: JSON.stringify(fieldsList)},
+      dataType: 'json',
+    });
   }
 
   /**