avoid use of shallow (#636)

this probably has some tiny overhead but it shouldn't practically matter

eth/p2p/discovery.nim

@@ -132,7 +132,6 @@ proc sendNeighbours*(d: DiscoveryProtocol, node: Node, neighbours: seq[Node]) =
   const MAX_NEIGHBOURS_PER_PACKET = 12 # TODO: Implement a smarter way to compute it
   type Neighbour = tuple[ip: IpAddress, udpPort, tcpPort: Port, pk: PublicKey]
   var nodes = newSeqOfCap[Neighbour](MAX_NEIGHBOURS_PER_PACKET)
-  shallow(nodes)
 
   template flush() =
     block:

tests/p2p/test_rlpx_thunk.nim

@@ -2,9 +2,9 @@
 
 import
   std/[json, os],
-  unittest2, stint,
+  unittest2,
   chronos, stew/byteutils,
-  ../../eth/[p2p, common],
+  ../../eth/[p2p],
   ../stubloglevel,
   ./p2p_test_helper,
   ./eth_protocol