Add logback configuration file to MQTT Java test project

(cherry picked from commit b0dc491)

Author: acogoluegnes

deps/rabbitmq_mqtt/test/java_SUITE_data/src/test/resources/logback-test.xml

@@ -0,0 +1,13 @@
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <logger name="com.rabbitmq" level="info" />
+
+    <root level="warn">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>