MINOR. Fix 2.3.0 streams systest dockerfile typo (#7272)
MINOR. Fix 2.3.0 streams systest dockerfile typo (#7272)

As part of commit 4d1ee26a136997d31dbd6ddca07e09b34c41c77d streams
version 2.3.0 test jar was added, but there was a simple typo in the
path that specified the version.

`ducker-ak up` was failing because of that. Fixed that.

Reviewers: Guozhang Wang <fae442ba222671b2ebdf7511c9ca77079c43031b@gmail.com>
guozhangwang/kafka,sslavic/kafka,Chasego/kafka,lindong28/kafka,Chasego/kafka,guozhangwang/kafka,sslavic/kafka,lindong28/kafka,TiVo/kafka,Chasego/kafka,TiVo/kafka,guozhangwang/kafka,lindong28/kafka,sslavic/kafka,noslowerdna/kafka,apache/kafka,noslowerdna/kafka,sslavic/kafka,apache/kafka,guozhangwang/kafka,apache/kafka,noslowerdna/kafka,lindong28/kafka,TiVo/kafka,apache/kafka,noslowerdna/kafka,Chasego/kafka,TiVo/kafka