add maven dependencies for mqtt

examples/pom.xml

@@ -125,6 +125,11 @@
         </exclusion>
       </exclusions>
     </dependency>
+    <dependency>
+      <groupId>org.eclipse.paho</groupId>
+      <artifactId>mqtt-client</artifactId>
+       <version>0.4.0</version>
+    </dependency>
   </dependencies>
 
   <profiles>