rec: don't use a vector of string for internal pubsuffixlist

rec: don't use a vector of string for internal pubsuffixlist

The construct

std::vector<std::string> x  { not event that many string literals };

blows up with some compilers. Worst I have seen is (with not even
8k strings): g++12 develops a resident size of 26G.

This just creates a (blank line and comments stripped) in-memory version of the file that is
fed to the same code as an external file.

Problem noted by @wojas.

Signed-off-by: Otto Moerbeek <otto.moerbeek@open-xchange.com>