Fix typo in docs

Author: David Christensen

check_postgres.pl

@@ -9491,7 +9491,7 @@ =head2 B<last_autovacuum>
 
 Example 2: Same as above, but skip tables belonging to the users 'eve' or 'mallory'
 
-  check_postgres_last_vacuum --host=wormwood --warning='3d' --critical='7d' --excludeusers=eve,mallory
+  check_postgres_last_vacuum --host=wormwood --warning='3d' --critical='7d' --excludeuser=eve,mallory
 
 For MRTG output, returns (on the first line) the LEAST amount of time in seconds since a table was 
 last vacuumed or analyzed. The fourth line returns the name of the database and name of the table.

check_postgres.pl.html

@@ -926,7 +926,7 @@ <h2 id="last_autovacuum"><b>last_autovacuum</b></h2>
 
 <p>Example 2: Same as above, but skip tables belonging to the users &#39;eve&#39; or &#39;mallory&#39;</p>
 
-<pre><code>  check_postgres_last_vacuum --host=wormwood --warning=&#39;3d&#39; --critical=&#39;7d&#39; --excludeusers=eve,mallory</code></pre>
+<pre><code>  check_postgres_last_vacuum --host=wormwood --warning=&#39;3d&#39; --critical=&#39;7d&#39; --excludeuser=eve,mallory</code></pre>
 
 <p>For MRTG output, returns (on the first line) the LEAST amount of time in seconds since a table was last vacuumed or analyzed. The fourth line returns the name of the database and name of the table.</p>