Use icon helper

app/views/admin/system_info/show.html.haml

@@ -12,7 +12,7 @@
           - if @cpus
             %h1= "#{@cpus.length} cores"
           - else
-            %i.fa.fa-warning.text-warning
+            = icon('warning', class: 'text-warning')
             Unable to collect CPU info
     .col-sm-4
       .light-well
@@ -21,7 +21,7 @@
           - if @memory
             %h1= "#{number_to_human_size(@memory.active_bytes)} / #{number_to_human_size(@memory.total_bytes)}"
           - else
-            %i.fa.fa-warning.text-warning
+            = icon('warning', class: 'text-warning')
             Unable to collect memory info
     .col-sm-4
       .light-well