Fixed Sonar Blocker in StatisticsServlet
Fixed 4 Blocker issues in StatisticsServlet.java
https://sonar.onap.org/project/issues?id=org.onap.dmaap.datarouter%3Aparent&open=
AWHFaQmXEU5FCDfKtnMB&resolved=false&severities=BLOCKER&types=BUG
https://sonar.onap.org/project/issues?id=org.onap.dmaap.datarouter%3Aparent&open=
AWHFaQmXEU5FCDfKtnL-&resolved=false&severities=BLOCKER&types=BUG
https://sonar.onap.org/project/issues?id=org.onap.dmaap.datarouter%3Aparent&open=
AWHFaQmXEU5FCDfKtnL_&resolved=false&severities=BLOCKER&types=BUG
https://sonar.onap.org/project/issues?id=org.onap.dmaap.datarouter%3Aparent&open
=AWHFaQmXEU5FCDfKtnMA&resolved=false&severities=BLOCKER&types=BUG
Issue-ID: DMAAP-674
Change-Id: I3dbc50523e0fda002c0a26fa05b23814bf8563bc
Signed-off-by: Amaresh Kumar <kamaresh@in.ibm.com>