Fix minor exception issues (#550)

Makes code compatible with
https://github.com/status-im/nim-chronos/pull/166 without requiring it.

libp2p/stream/connection.nim

@@ -41,7 +41,7 @@ proc isUpgraded*(s: Connection): bool =
   if not isNil(s.upgraded):
     return s.upgraded.finished
 
-proc upgrade*(s: Connection, failed: ref Exception = nil) =
+proc upgrade*(s: Connection, failed: ref CatchableError = nil) =
   if not isNil(s.upgraded):
     if not isNil(failed):
       s.upgraded.fail(failed)

libp2p/switch.nim

@@ -85,8 +85,6 @@ proc removePeerEventHandler*(s: Switch,
                              kind: PeerEventKind) =
   s.connManager.removePeerEventHandler(handler, kind)
 
-proc disconnect*(s: Switch, peerId: PeerID) {.async, gcsafe.}
-
 proc isConnected*(s: Switch, peerId: PeerID): bool =
   ## returns true if the peer has one or more
   ## associated connections (sockets)

libp2p/transports/tcptransport.nim

@@ -35,7 +35,7 @@ type
     opened*: uint64
     closed*: uint64
 
-proc setupTcpTransportTracker(): TcpTransportTracker {.gcsafe.}
+proc setupTcpTransportTracker(): TcpTransportTracker {.gcsafe, raises: [Defect].}
 
 proc getTcpTransportTracker(): TcpTransportTracker {.gcsafe.} =
   result = cast[TcpTransportTracker](getTracker(TcpTransportTrackerName))