Fix reference to vert.x MQTT server source code.

Author: Kai Hudalla

legal/legal/about.html

@@ -219,17 +219,16 @@ <h5>Spring Boot ${spring-boot.version}</h5>
 is included without modifications. The source code is available from
 <a href='http://search.maven.org/#search|ga|1|g:"org.springframework.boot"%20AND%20v:"${spring-boot.version}"%20AND%20l:"sources"'>Maven Central</a>.
 
-<h5>vert.x MQTT ${vertx-mqtt.version}</h5>
+<h5>vert.x MQTT Server ${vertx-mqtt.version}</h5>
 
 <p>This product includes software developed by the <a href="http://vertx.io">vert.x project</a>.</p>
 
-<p>Your use of <em>vert.x MQTT</em> is subject to the terms and conditions of the Apache Software License 2.0.
+<p>Your use of <em>vert.x MQTT Server</em> is subject to the terms and conditions of the Apache Software License 2.0.
 A copy of the license is contained in the file <a href="LICENSE-2.0.txt">LICENSE-2.0.txt</a> and is also available at
 <a href="http://www.apache.org/licenses/LICENSE-2.0.html">http://www.apache.org/licenses/LICENSE-2.0.html</a>.</p>
 
 <p>The binary code in <em>vertx-mqtt-server-${vertx-mqtt.version}.jar</em> is included without modifications.
-The source code is available from
-<a href="https://oss.sonatype.org/content/repositories/snapshots/io/vertx/vertx-mqtt-server/3.4.0-SNAPSHOT/vertx-mqtt-server-${vertx-mqtt.version}-sources.jar">Sonatype Snapshot Repository</a>.
+The source code is available from < href="https://github.com/vert-x3/vertx-mqtt-server">GitHub</a>.
 </p>
 
 <h5>vert.x Proton ${vertx-proton.version}</h5>