Simplify modifyUrlParams to fix bugs with extra tokens.

app/assets/javascripts/service_desk_issues/filtered_search.js

@@ -12,13 +12,17 @@ export default class FilteredSearchServiceDesk extends gl.FilteredSearchManager
   }
 
   modifyUrlParams(paramsArray) {
-    const paramKey = 'author_username';
+    const authorParamKey = 'author_username';
     // FIXME: Need to grab the value from a data attribute
-    const supportBotParamPair = `${paramKey}=support-bot`;
+    const supportBotParamPair = `${authorParamKey}=support-bot`;
 
-    return paramsArray.map((param) => {
-      return param.indexOf(paramKey) === -1 ? param : supportBotParamPair;
+    const onlyValidParams = paramsArray.filter((param) => {
+      return param.indexOf(authorParamKey) === -1;
     });
+
+    onlyValidParams.push(supportBotParamPair);
+
+    return onlyValidParams;
   }
 }