Shorten the search input for "text with other filters" spec

The assignee wasn't important to the test, and shortening the query
allowed us to avoid the "horizontal scroll" failure without having to
stub the `sidebar_collapsed?` helper.

spec/features/issues/filtered_search/filter_issues_spec.rb

@@ -397,7 +397,7 @@ describe 'Filter issues', js: true do
 
     context 'searched text with other filters' do
       it 'filters issues by searched text, author, text, assignee, text, label1, text, label2, text, milestone and text' do
-        input_filtered_search("bug author:@#{user.username} assignee:@#{user.username} report label:~#{bug_label.title} label:~#{caps_sensitive_label.title} milestone:%#{milestone.title} foo")
+        input_filtered_search("bug author:@#{user.username} report label:~#{bug_label.title} label:~#{caps_sensitive_label.title} milestone:%#{milestone.title} foo")
 
         expect_issues_list_count(1)
         expect_filtered_search_input('bug report foo')