Warn about downgrading to 0.8.x
Warn about downgrading to 0.8.x

Fixes #3782

nsacoin/nsacoin,Domer85/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,langerhans/dogecoin,Exceltior/dogecoin,coinwarp/dogecoin,coinwarp/dogecoin,marklai9999/Taiwancoin,Domer85/dogecoin,Exceltior/dogecoin,coinwarp/dogecoin,marklai9999/Taiwancoin,masterbraz/dg,RazorLove/cloaked-octo-spice,jarymoth/dogecoin,nsacoin/nsacoin,koharjidan/dogecoin,Exceltior/dogecoin,jarymoth/dogecoin,nsacoin/nsacoin,brishtiteveja/sherlockcoin,riecoin/riecoin,haisee/dogecoin,nigeriacoin/nigeriacoin,koharjidan/dogecoin,riecoin/riecoin,nigeriacoin/nigeriacoin,haisee/dogecoin,brishtiteveja/sherlockcoin,coinkeeper/2015-06-22_18-37_dogecoin,Domer85/dogecoin,koharjidan/dogecoin,langerhans/dogecoin,nigeriacoin/nigeriacoin,oklink-dev/bitcoin_block,coinkeeper/2015-06-22_18-37_dogecoin,jarymoth/dogecoin,haisee/dogecoin,langerhans/dogecoin,nigeriacoin/nigeriacoin,oklink-dev/bitcoin_block,riecoin/riecoin,masterbraz/dg,oklink-dev/bitcoin_block,nsacoin/nsacoin,masterbraz/dg,Exceltior/dogecoin,coinwarp/dogecoin,koharjidan/dogecoin,masterbraz/dg,langerhans/dogecoin,Domer85/dogecoin,brishtiteveja/sherlockcoin,nsacoin/nsacoin,marklai9999/Taiwancoin,koharjidan/dogecoin,langerhans/dogecoin,marklai9999/Taiwancoin,RazorLove/cloaked-octo-spice,oklink-dev/bitcoin_block,oklink-dev/bitcoin_block,riecoin/riecoin,jarymoth/dogecoin,riecoin/riecoin,jarymoth/dogecoin,masterbraz/dg,koharjidan/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,RazorLove/cloaked-octo-spice,haisee/dogecoin,brishtiteveja/sherlockcoin,Exceltior/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,nigeriacoin/nigeriacoin,haisee/dogecoin,RazorLove/cloaked-octo-spice,brishtiteveja/sherlockcoin,coinwarp/dogecoin,RazorLove/cloaked-octo-spice,langerhans/dogecoin,oklink-dev/bitcoin_block