Request for updating libc version

[happys2333]

I think that we should update our system libc. Here is a problem when I try to run victoria3 through steam.

./victoria3: /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.26' not found (required by ./victoria3)

This shows our libc are too old.

[BLumia]

Should be updated in v23 (alpha version release will be in the upcoming week).

Since glibc update could break a lots of app so we probably won't update it in v20.