Use safetyCatch err handlers instead of noop

[HDegroote]

Note: I could not figure out why the noop-err-listener was removed here:

hyperswarm/index.js

Line 178 in 21390bf

conn.removeListener('error', noop)

. No noop-error-handler seems to be set in that method, and in hyperdht's connect method it's only set in only one place which seems irrelevant: https://github.com/holepunchto/hyperdht/blob/4e30215fd7e75370516df35abafe174d43b26ac5/lib/connect.js#L411

If we want to be safe, we could remove both a noop and a safetyCatch handler there, although it seems plausible that neither is needed.

For now it's just removing a safetyCatch listener, which should be compat with hyperdht as it's no longer using noop handlers once holepunchto/hyperdht#154 is in