Reduce compiler warnings related to rlp encode int (#699)

eth/p2p/discovery.nim

@@ -52,7 +52,7 @@ proc append*(w: var RlpWriter, a: IpAddress) =
   of IpAddressFamily.IPv4:
     w.append(a.address_v4)
 
-proc append(w: var RlpWriter, p: Port) = w.append(p.int)
+proc append(w: var RlpWriter, p: Port) = w.append(p.uint)
 proc append(w: var RlpWriter, pk: PublicKey) = w.append(pk.toRaw())
 proc append(w: var RlpWriter, h: MDigest[256]) = w.append(h.data)
 
@@ -114,7 +114,7 @@ proc send(d: DiscoveryProtocol, n: Node, data: seq[byte]) =
   f.addCallback cb
 
 proc sendPing*(d: DiscoveryProtocol, n: Node): seq[byte] =
-  let payload = rlp.encode((PROTO_VERSION, d.address, n.node.address,
+  let payload = rlp.encode((PROTO_VERSION.uint, d.address, n.node.address,
                             expiration()))
   let msg = pack(cmdPing, payload, d.privKey)
   result = msg[0 ..< MAC_SIZE]

eth/p2p/rlpx.nim

@@ -1000,7 +1000,7 @@ proc p2pProtocolBackendImpl*(protocol: P2PProtocol): Backend =
       var `rlpWriter` = `initRlpWriter`()
       const `perProtocolMsgIdVar` {.used.} = `msgId`
       let `perPeerMsgIdVar` = `perPeerMsgIdValue`
-      `append`(`rlpWriter`, `perPeerMsgIdVar`)
+      `append`(`rlpWriter`, `perPeerMsgIdVar`.uint)
 
     when tracingEnabled:
       appendParams.add logSentMsgFields(peerVar, protocol, msgId, paramsToWrite)
@@ -1032,6 +1032,7 @@ proc p2pProtocolBackendImpl*(protocol: P2PProtocol): Backend =
                    newLit(protocol.version),
                    protocol.peerInit, protocol.netInit)
 
+
 p2pProtocol DevP2P(version = 5, rlpxName = "p2p"):
   proc hello(peer: Peer,
              version: uint,

eth/trie/hexary.nim

@@ -460,7 +460,7 @@ proc mergeAndGraft(self: var HexaryTrie;
     output.append hexPrefixEncode(NibblesSeq(), true)
   else:
     doAssert(not soleChild.isEmpty)
-    output.append int(hexPrefixEncodeByte(childPos))
+    output.append uint(hexPrefixEncodeByte(childPos))
   output.append(soleChild)
   result = output.finish()