Fix code background missing a pixel

Yes, a single pixel.
diff --git a/static/css/style.less b/static/css/style.less
index 88f7f01..22ac6dc 100644
--- a/static/css/style.less
+++ b/static/css/style.less
@@ -183,6 +183,10 @@
           border: none;
         }
 
+        td {
+          padding: 0px;
+        }
+
         td.linenos {
           width: 30px;
           overflow: hidden;