Fixed list issues not loading with spaces in filtered values

Vue resource is kindly encoding our URL params but Rails sadly doesn't seem to understand them.

Closes #21920

app/assets/javascripts/lib/utils/url_utility.js

@@ -17,7 +17,7 @@
       while (i < sURLVariables.length) {
         sParameterName = sURLVariables[i].split('=');
         if (sParameterName[0] === sParam) {
-          values.push(sParameterName[1]);
+          values.push(sParameterName[1].replace(/\+/g, ' '));
         }
         i++;
       }

spec/features/boards/boards_spec.rb

@@ -61,6 +61,7 @@ describe 'Issue Boards', feature: true, js: true do
     let(:bug)         { create(:label, project: project, name: 'Bug') }
     let!(:backlog)    { create(:label, project: project, name: 'Backlog') }
     let!(:done)       { create(:label, project: project, name: 'Done') }
+    let!(:accepting)  { create(:label, project: project, name: 'Accepting Merge Requests') }
     let!(:list1) { create(:list, board: project.board, label: planning, position: 0) }
     let!(:list2) { create(:list, board: project.board, label: development, position: 1) }
@@ -74,7 +75,7 @@ describe 'Issue Boards', feature: true, js: true do
     let!(:issue6) { create(:labeled_issue, project: project, labels: [planning, development]) }
     let!(:issue7) { create(:labeled_issue, project: project, labels: [development]) }
     let!(:issue8) { create(:closed_issue, project: project) }
-    let!(:issue9) { create(:labeled_issue, project: project, labels: [testing, bug]) }
+    let!(:issue9) { create(:labeled_issue, project: project, labels: [testing, bug, accepting]) }
     before do
       visit namespace_project_board_path(project.namespace, project)
@@ -467,6 +468,34 @@ describe 'Issue Boards', feature: true, js: true do
         end
       end
+      it 'filters by label with space after reload' do
+        page.within '.issues-filters' do
+          click_button('Label')
+          wait_for_ajax
+
+          page.within '.dropdown-menu-labels' do
+            click_link(accepting.title)
+            wait_for_vue_resource(spinner: false)
+            find('.dropdown-menu-close').click
+          end
+        end
+
+        # Test after reload
+        page.evaluate_script 'window.location.reload()'
+
+        wait_for_vue_resource
+
+        page.within(find('.board', match: :first)) do
+          expect(page.find('.board-header')).to have_content('1')
+          expect(page).to have_selector('.card', count: 1)
+        end
+
+        page.within(find('.board:nth-child(2)')) do
+          expect(page.find('.board-header')).to have_content('0')
+          expect(page).to have_selector('.card', count: 0)
+        end
+      end
+
       it 'infinite scrolls list with label filter' do
         50.times do
           create(:labeled_issue, project: project, labels: [testing])