Fix lines and line numbers being squashed in File -> blame

app/views/blame/show.html.haml

@@ -38,9 +38,11 @@
                   - current_line += 1
                 - else
                   - lines.each do |line|
-                    = current_line
+                    :preserve
+                      #{current_line}
                     - current_line += 1
             %td.lines
               %pre
                 - lines.each do |line|
-                  = line
+                  :preserve
+                    #{line}