MINOR: Remove # from .bat start script
MINOR: Remove # from .bat start script

On Windows, the following output is seen when starting Zookeeper and Kafka servers:
```
'#' is not recognized as an internal or external command,
operable program or batch file.
```

This pull request makes a minor correction to the Windows `kafka-run-class.bat` script to replace the use of `#` with `rem`.

Author: P. Thorpe <paul.thorpe@uk.ibm.com>

Reviewers: Vahid Hashemian, Gwen Shapira

Closes #1740 from p-thorpe/trunk

Ishiihara/kafka,eribeiro/kafka,richhaase/kafka,Ishiihara/kafka,TiVo/kafka,Esquive/kafka,ErikKringen/kafka,TiVo/kafka,ErikKringen/kafka,rhauch/kafka,sebadiaz/kafka,richhaase/kafka,sebadiaz/kafka,apache/kafka,lindong28/kafka,mihbor/kafka,Esquive/kafka,KevinLiLu/kafka,richhaase/kafka,richhaase/kafka,ollie314/kafka,rhauch/kafka,noslowerdna/kafka,ijuma/kafka,mihbor/kafka,sslavic/kafka,MyPureCloud/kafka,MyPureCloud/kafka,MyPureCloud/kafka,sslavic/kafka,noslowerdna/kafka,ollie314/kafka,KevinLiLu/kafka,Ishiihara/kafka,guozhangwang/kafka,airbnb/kafka,gf53520/kafka,themarkypantz/kafka,themarkypantz/kafka,TiVo/kafka,themarkypantz/kafka,Esquive/kafka,gf53520/kafka,geeag/kafka,Chasego/kafka,KevinLiLu/kafka,Chasego/kafka,lindong28/kafka,geeag/kafka,rhauch/kafka,apache/kafka,ijuma/kafka,lindong28/kafka,TiVo/kafka,gf53520/kafka,airbnb/kafka,eribeiro/kafka,ijuma/kafka,MyPureCloud/kafka,mihbor/kafka,rhauch/kafka,eribeiro/kafka,geeag/kafka,sslavic/kafka,apache/kafka,noslowerdna/kafka,Chasego/kafka,guozhangwang/kafka,Ishiihara/kafka,airbnb/kafka,themarkypantz/kafka,guozhangwang/kafka,mihbor/kafka,ErikKringen/kafka,gf53520/kafka,ijuma/kafka,KevinLiLu/kafka,ollie314/kafka,sebadiaz/kafka,sslavic/kafka,sebadiaz/kafka,airbnb/kafka,noslowerdna/kafka,Esquive/kafka,apache/kafka,eribeiro/kafka,geeag/kafka,guozhangwang/kafka,ErikKringen/kafka,ollie314/kafka,lindong28/kafka,Chasego/kafka