can't compile jdbcT4 for no slf4j

["shengchen.ma@esgyn.cn" <sh...@esgyn.cn>]

hi all :
Today when I was installing apache trafodion in a new env, I met the  follow problem in jdbc :
Could not transfer artifact org.slf4j:slf4j-jdk14:pom:1.7.21 from/to central (https://repo.maven.apache.org/maven2): Received fatal alert: protocol_version

I seached why this happened, then I found it does not support TLSv1.1 since 2018-6-18. see : https://central.sonatype.org/articles/2018/May/04/discontinued-support-for-tlsv11-and-below/ 
so I do a PR https://github.com/apache/trafodion/pull/1765 to fix it .

If someone meets the same problem , you can do export MAVEN_OPTS=-Dhttps.protocols=TLSv1,TLSv1.1,TLSv1.2 temporary.


regards,
shengchen.ma