Use a one-line if condition in proposals index

With the multiline condition, HTML Beautifier (which we're about to
introduce in order to manage ERB indentation) gets confused. In this
context, a one-line condition is also more readable.

app/views/proposals/index.html.erb

@@ -8,12 +8,7 @@
   <%= render "shared/canonical", href: proposals_url %>
 <% end %>
 
-<% if [
+<% if [@search_terms, @advanced_search_terms, params[:retired].present?, params[:selected].present?].any? %>
-        @search_terms,
-        @advanced_search_terms,
-        params[:retired].present?,
-        params[:selected].present?
-      ].any? %>
   <%= render Shared::SearchResultsSummaryComponent.new(
     results: @proposals,
     search_terms: @search_terms,