Bump org.eclipse.paho.client.mqttv3 in /platforms/java7/connectors/mqtt

Bumps org.eclipse.paho.client.mqttv3 from 1.1.0 to 1.2.1.

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/platforms/java7/connectors/mqtt/pom.xml b/platforms/java7/connectors/mqtt/pom.xml
index 3a1b73a..418ac8e 100644
--- a/platforms/java7/connectors/mqtt/pom.xml
+++ b/platforms/java7/connectors/mqtt/pom.xml
@@ -101,7 +101,7 @@
     <dependency>
       <groupId>org.eclipse.paho</groupId>
       <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
-      <version>1.1.0</version>
+      <version>1.2.1</version>
     </dependency>
 
     <dependency>