MINOR: Fix docs in security.html (#461)

Reviewers: Mickael Maison <mickael.maison@gmail.com>

33/security.html

@@ -1516,7 +1516,7 @@ <h4 class="anchor-heading"><a id="security_authz_examples" class="anchor-link"><
             Suppose you want to add an acl "Principals User:Bob and User:Alice are allowed to perform Operation Read and Write on Topic Test-Topic from IP 198.51.100.0 and IP 198.51.100.1". You can do that by executing the CLI with following options:
             <pre class="line-numbers"><code class="language-bash">&gt; bin/kafka-acls.sh --authorizer-properties zookeeper.connect=localhost:2181 --add --allow-principal User:Bob --allow-principal User:Alice --allow-host 198.51.100.0 --allow-host 198.51.100.1 --operation Read --operation Write --topic Test-topic</code></pre>
             By default, all principals that don't have an explicit acl that allows access for an operation to a resource are denied. In rare cases where an allow acl is defined that allows access to all but some principal we will have to use the --deny-principal and --deny-host option. For example, if we want to allow all users to Read from Test-topic but only deny User:BadBob from IP 198.51.100.3 we can do so using following commands:
-            <pre class="line-numbers"><code class="language-bash">&gt; bin/kafka-acls.sh --authorizer-properties zookeeper.connect=localhost:2181 --add --allow-principal User:* --allow-host * --deny-principal User:BadBob --deny-host 198.51.100.3 --operation Read --topic Test-topic</code></pre>
+            <pre class="line-numbers"><code class="language-bash">&gt; bin/kafka-acls.sh --authorizer-properties zookeeper.connect=localhost:2181 --add --allow-principal User:'*' --allow-host '*' --deny-principal User:BadBob --deny-host 198.51.100.3 --operation Read --topic Test-topic</code></pre>
             Note that <code>--allow-host</code> and <code>--deny-host</code> only support IP addresses (hostnames are not supported).
             Above examples add acls to a topic by specifying --topic [topic-name] as the resource pattern option. Similarly user can add acls to cluster by specifying --cluster and to a consumer group by specifying --group [group-name].
             You can add acls on any resource of a certain type, e.g. suppose you wanted to add an acl "Principal User:Peter is allowed to produce to any Topic from IP 198.51.200.0"