It is grabbing Opera 12.11 installer (which was updated 11/19/12) from the FTP, but should grab 12.18 from the FTP (2/15/16 still runs on XP)
old
ftp://ftp.opera.com/pub/opera/win/1211/int/Opera_1211_int_Setup.exe
new
ftp://ftp.opera.com/pub/opera/win/1218/int/Opera_1218_int_Setup.exe
See http://www.opera.com/blogs/security/2016/02/opera-12-and-opera-mail-security-update/ for more info about the security update (also gives more certificate support as mentioned in the blog post from Opera Software