www: add print_content_box for naturally-padded content

(cherry picked from commit bf937657)

src/www/guiconfig.inc

@@ -218,6 +218,17 @@ function print_alert_box($msg, $alert = 'warning', $button = '')
 EOFnp;
 }
 
+function print_content_box($msg)
+{
+	echo <<<EOFnp
+<div class="table-responsive">
+  <table class="table table-striped">
+     <tr><td>{$msg}</td></tr>
+  </table>
+</div>
+EOFnp;
+}
+
 function print_info_box_apply($msg)
 {
 	$iface = !empty($_POST['if']) ? $_POST['if'] : (!empty($_GET['if']) ? $_GET['if'] : '');

src/www/services_dhcpv6.php

@@ -463,9 +463,9 @@ include("head.inc");
         <div class="tab-content content-box col-xs-12">
           <form method="post" name="iform" id="iform">
               <?php if (!empty($config['dhcrelay6']['enabled'])): ?>
-              <p><?= gettext('DHCP Relay is currently enabled. Cannot enable the DHCP Server service while the DHCP Relay is enabled on any interface.') ?></p>
+              <?php print_content_box(gettext('DHCP Relay is currently enabled. Cannot enable the DHCP Server service while the DHCP Relay is enabled on any interface.')); ?></p>
               <?php elseif (count($tab_array_main) == 0):?>
-              <?php print_info_box(("No interfaces found with a static IPv6 address.")); ?>
+              <?php print_content_box(gettext('No interfaces found with a static IPv6 address.')); ?>
               <?php else: ?>
                 <div class="table-responsive">
                   <table class="table table-striped">

src/www/services_router_advertisements.php

@@ -193,7 +193,7 @@ include("head.inc");
           <div class="tab-content content-box col-xs-12">
             <form method="post" name="iform" id="iform">
             <?php if (count($tab_array_main) == 0):?>
-            <?php print_info_box(("No interfaces found with a static IPv6 address.")); ?>
+            <?php print_content_box(gettext('No interfaces found with a static IPv6 address.')); ?>
             <?php else: ?>
               <div class="table-responsive">
                 <table class="table table-striped">