make tun dependency optional (#142)

* remove log crates
* remove udp/raw of smoltcp
* make tun as optional dependancy, compile for freebsd works

Cargo.lock

@@ -1271,7 +1271,6 @@ dependencies = [
  "http 1.1.0",
  "humansize",
  "indexmap 1.9.3",
- "log",
  "mimalloc-rust",
  "network-interface",
  "nix 0.27.1",
@@ -4561,8 +4560,6 @@ dependencies = [
  "cfg-if",
  "defmt",
  "heapless 0.8.0",
- "libc",
- "log",
  "managed",
 ]