Use absolute translation paths

Using `t(.empty_proposals)` IMHO is a bit dangerous because we'd need to
change the locale files if we move the code to a partial or rename the
file.

app/views/legislation/processes/proposals.html.erb

@@ -11,7 +11,7 @@
         <div class="legislation-proposals">
           <% if @proposals.empty? %>
             <div class="callout primary">
-              <p><%= t('.empty_proposals') %></p>
+              <p><%= t("legislation.processes.proposals.empty_proposals") %></p>
             </div>
           <% else %>
             <%= render @proposals %>