TAJO-795: Enclose the sql logs of DBStore into the isDebugEnabled condition
TAJO-795: Enclose the sql logs of DBStore into the isDebugEnabled condition

Change-Id: I5517ff2249623b6739ca4f752f857c808face986
Reviewed-on: https://dbserver.korea.ac.kr/reviews/228
Tested-by:  Jenkins <80754af91bfb6d1073585b046fe0a474ce868509@dbserver.korea.ac.kr>
Reviewed-by: Hyunsik Choi <05a3172daee8e68f070c7e3940f4ecf228130ad0@gmail.com>

apache/incubator-tajo,yeeunshim/tajo_test,apache/incubator-tajo,gruter/tajo-cdh,hyunsik/incubator-tajo,yeeunshim/tajo_test,apache/incubator-tajo,apache/incubator-tajo,gruter/tajo-cdh,yeeunshim/tajo_test,hyunsik/incubator-tajo,hyunsik/incubator-tajo,yeeunshim/tajo_test,gruter/tajo-cdh,gruter/tajo-cdh,hyunsik/incubator-tajo