Fix grammar.

templates/front/welcome.html

@@ -16,7 +16,7 @@
         <strong>When this address is not requested for a set time period, you will get alerted.</strong> Below are snippets that are ready to be copy/pasted into your own scripts.</p>
     </div>
     <div class="col-sm-6 col-sm-pull-6">
-        <h2 id="pitch-subtitle">Here's an unique ping address for you:</h2>
+        <h2 id="pitch-subtitle">Here's a unique ping address for you:</h2>
         <div id="pitch-url">
             <input
                 id="pitch-url-input"