Remove unused Makefile variables
Remove unused Makefile variables

Fixes #176.

yiliaofan/hiredis,nherment/arsenic,Yhgenomics/hiredis,hidebug/hiredis,Yhgenomics/hiredis,thomaslee/hiredis,chenlicong0821/hiredis,redis/hiredis,liulingfree/hiredis,redis/hiredis,chenlicong0821/hiredis,tattsun/hiredis,thedrow/hiredis,xjzhou/hiredis,charsyam/hiredis,nokiddin/hiredis,owent-contrib/hiredis,arinal/hiredis,rangan337/hiredis,picrin/redisSamples,olgeni/hiredis,jqk6/hiredis,Microsoft/hiredis,rangan337/hiredis,xjzhou/hiredis,h1048576/hiredis,jinguoli/hiredis,owent-contrib/hiredis,jinguoli/hiredis,thomaslee/hiredis,galdor/hiredis,charsyam/hiredis,jinguoli/hiredis,galdor/hiredis,hidebug/hiredis,redis/hiredis,tattsun/hiredis,badboy/hiredis-win,Microsoft/hiredis,olgeni/hiredis,liulingfree/hiredis