Fix issue with the first row in the all rooms view being very high in…

… Firefox. See GitHub Issue #3726.  (Not quite sure what problem that CSS rule was trying to solve in the first place and why it's no longer necessary.)

web/css/mrbs.css.php

@@ -279,10 +279,6 @@
   background-color: <?php echo $row_even_color_weekend_holiday ?>;
 }
 
-.all_rooms td {
-  height: 100%; <?php // for Firefox ?>
-}
-
 .dwm_main.all_rooms td a {
   display: flex;
   height: 100%;