Fix release number

docs/views/how-tos/publish-your-prototype-online.html

@@ -37,7 +37,7 @@ <h2>Setting a password</h2>
       <p>To set a password, check your hosting services documentation on how to set "environment variables". (It may have a slightly different name like "config vars" or "variables".)</p>
       <p>The password should be set using the variable <code class="app-code">PROTOTYPE_PASSWORD</code>.</p>
 
-      <p>If you are using an older version of the prototype kit (before v4.12.9) you will also need to set a username using the variable <code class="app-code">PROTOTYPE_USERNAME</code>.</p>
+      <p>If you are using an older version of the prototype kit (before v4.12.0) you will also need to set a username using the variable <code class="app-code">PROTOTYPE_USERNAME</code>.</p>
 
       <p>In Railway, you also need to create:</p>
       <ul>