add referral_link only if referral_link is nil in session
add referral_link only if referral_link is nil in session

mrmarcondes/catarse,carmenmp/catarse,devton/catarse,williamair1/catarse,ripple0328/catarse,catarse/catarse,wlads/catarse,JamesUcci/webapplication,diegorv/catarse,ujjwalkhanal/helpbegin,nicolasiensen/labcriativo,coopsource/catarse,ujjwalkhanal/helpbegin,mrmarcondes/catarse,elesban/catarse,coopsource/catarse,Saharitte/catarse,devton/catarse,paulopatto/catarse,paulodarosa/catarse,carmenmp/catarse,liberland/catarse,paulodarosa/pollis.co,victor95pc/catarse,magyarmosoly/akimasnakoktatas,Saharitte/catarse,thiagocatarse/catarse,nicolasiensen/bookstart,sushant12/jvn,nicolasiensen/labcriativo,umeshduggal/flockaway,diraulo/catarse,liberland/catarse,elesban/catarse,juanmanunez/catarse,paulodarosa/mudabr,egozo/producerun,stephenhack/yhacks,danielweinmann/catarse,liberland/catarse,diogob/catarse,danielweinmann/catarse,mrmarcondes/catarse,Haseeb-Qureshi/catarse,globalavocado/catarse,rokibulhassan/catarse,paulodarosa/crowd,adrianob/catarse,catarse/catarse,sushant12/jvn,diogob/catarse,diegorv/catarse,adrianob/99gamers,ripple0328/catarse,magyarmosoly/akimasnakoktatas,adrianob/99gamers,rokibulhassan/catarse,diegorv/catarse,vandofb/catarse,nicolasiensen/labcriativo,globalavocado/catarse,vandofb/catarse,diraulo/catarse,wlads/catarse,wlads/catarse,Haseeb-Qureshi/catarse,ujjwalkhanal/helpbegin,paulopatto/catarse,ripple0328/catarse,egozo/producerun,JamesUcci/webapplication,stephenhack/yhacks,JamesUcci/webapplication,paulopatto/catarse,sushant12/jvn,devton/catarse,catarse/catarse,stephenhack/yhacks,adrianob/99gamers,Saharitte/catarse,juanmanunez/catarse,paulodarosa/catarse,diraulo/catarse,rokibulhassan/catarse,gumanoz/catarse,catarse/catarse,nicolasiensen/bookstart,magyarmosoly/akimasnakoktatas,devton/catarse,paulodarosa/catarse,umeshduggal/flockaway,vandofb/catarse,andrewyong82/100pp,juanmanunez/catarse,paulodarosa/pollis.co,paulopatto/catarse,thiagocatarse/catarse,egozo/producerun,paulodarosa/pollis.co,vicnicius/catarse,andrewyong82/100pp,coopsource/catarse,ripple0328/catarse,Haseeb-Qureshi/catarse,victor95pc/catarse,globalavocado/catarse,elesban/catarse,umeshduggal/flockaway,williamair1/catarse,paulodarosa/crowd,williamair1/catarse,thiagocatarse/catarse,vicnicius/catarse,gumanoz/catarse,adrianob/catarse,victor95pc/catarse,sushant12/jvn,andrewyong82/100pp,diogob/catarse,ujjwalkhanal/helpbegin,adrianob/catarse,gumanoz/catarse,paulodarosa/mudabr,vicnicius/catarse