(style, opnsense_standard_table_form) reverse zebra to improve heading, drop first grid line

When using opnsense_standard_table_form on a table, the first visible row contains a top border (because the invisible mobile border is placed first).
The change sets border-top-width on the first td,th to 0px and swaps the zebra printing to keep things more consistent.

src/www/javascript/opnsense_legacy.js

@@ -110,9 +110,14 @@ function hook_stacked_form_tables(match)
                   root_node.find('tr:visible').each(function () {
                       $(this).css("background-color", "inherit");
                       $(this).children().css("background-color", "inherit");
-                      if ( index % 2 == 0) {
+                      if ( index % 2 != 0) {
                           $(this).css("background-color", root_node.data('stripe-color'));
                       }
+                      if (index == 0) {
+                          // hide first visible table grid line
+                          $(this).find('td, th').css('border-top-width', '0px');
+                      }
+
                       // skip generated mobile headers (group header+content on mobile)
                       if (!$(this).hasClass('opnsense-table-mobile-header')) {
                           ++index;