info: remove confusing warning about running under valgrind

info: remove confusing warning about running under valgrind

We're not actually doing anything differently anywhere when
we detect that we're running under valgrind, so let's not
print that confusing message that makes people wonder how
they can switch it off so they can valgrind the normal
code paths. Seeing that we're not doing that nor have done
so in the last 10 years we might just as well remove the
entire check actually.