[FIX] [Bootstrap] Uniform default table background

Also removed empty style and class arguments while I was at it

allianceauth/optimer/templates/optimer/dashboard.ops.html

@@ -7,7 +7,7 @@
             <h4 class="card-title text-center">{% translate "Upcoming Fleets" %}</h4>
             <div class="card-body">
                 <div style="height: 300px; overflow-y:auto;">
-                    <table class="table" style="--bs-table-bg: transparent;">
+                    <table class="table">
                         <thead>
                             <tr>
                                 <th class="text-center">{% translate "Operation" %}</th>