feat: Some tweaks for optimisation

Signed-off-by: A S Adil Mohammad <asadilmohammad2020@gmail.com>

Author: A S Adil Mohammad

src/main/java/com/ibm/eventstreams/connect/mqsource/MQSourceTask.java

@@ -425,7 +425,7 @@ private List<Message> pollSourceQueue(final int numberOfMessagesToBePolled) thro
         }
 
         log.debug("Polling for records");
-        final long startTime = System.currentTimeMillis();
+        final long pollEndTime = System.currentTimeMillis() + maxPollTime;
 
         Message message;
         do {
@@ -437,7 +437,7 @@ private List<Message> pollSourceQueue(final int numberOfMessagesToBePolled) thro
             message != null &&
             localList.size() < numberOfMessagesToBePolled &&
             !stopNow.get() &&
-            (maxPollTime <= 0 || (System.currentTimeMillis() - startTime) < maxPollTime)
+            (maxPollTime <= 0 || System.currentTimeMillis() < pollEndTime)
         );
 
         return localList;