Fix build under Solaris
Fix build under Solaris

Solaris doesn't define the TCP options we try to set.  Let's
ignore those under Solaris.

Closes #207

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