Documentation: update limits for grace time as well.

templates/front/docs_api.html

@@ -169,7 +169,7 @@ To create a "cron" check, specify the "schedule" and "tz" parameters.
         <td>
             <p>number, optional, default value: {{ default_grace }}.</p>
             <p>A number of seconds, the grace period for this check.</p>
-            <p>Minimum: 60 (one minute), maximum: 604800 (one week).</p>
+            <p>Minimum: 60 (one minute), maximum: 2592000 (30 days).</p>
         </td>
     </tr>
     <tr>
@@ -302,7 +302,7 @@ To create a "cron" check, specify the "schedule" and "tz" parameters.
         <td>
             <p>number, optional.</p>
             <p>A number of seconds, the grace period for this check.</p>
-            <p>Minimum: 60 (one minute), maximum: 604800 (one week).</p>
+            <p>Minimum: 60 (one minute), maximum: 2592000 (30 days).</p>
         </td>
     </tr>
     <tr>