Invalid conversion nodeID from Pubkey

[cortze]

Description

The crawler seems to be facing edgy cases where the node_id can not be extracted from the node's pubkey

Detailed log of the error:

ragno-ragno-1  | time="2023-10-05T16:26:14Z" level=info msg="closing peering dialer" dialer-id=5024
ragno-ragno-1  | panic: runtime error: invalid memory address or nil pointer dereference
ragno-ragno-1  | [signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x8edcae]
ragno-ragno-1  |
ragno-ragno-1  | goroutine 5266 [running]:
ragno-ragno-1  | github.com/ethereum/go-ethereum/p2p/enode.PubkeyToIDV4(0x0)
ragno-ragno-1  |        /ragno/go-ethereum/p2p/enode/urlv4.go:200 +0x4e
ragno-ragno-1  | github.com/cortze/ragno/crawler.(*Peering).connect(_, {{0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...}, ...})
ragno-ragno-1  |        /ragno/crawler/peering.go:169 +0x165
ragno-ragno-1  | github.com/cortze/ragno/crawler.(*Peering).Connect(0xc000316080, {{0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...}, ...})
ragno-ragno-1  |        /ragno/crawler/peering.go:159 +0xd3
ragno-ragno-1  | github.com/cortze/ragno/crawler.(*Peering).peeringWorker(0xc000316080, 0x0?)
ragno-ragno-1  |        /ragno/crawler/peering.go:151 +0x138
ragno-ragno-1  | created by github.com/cortze/ragno/crawler.(*Peering).Run
ragno-ragno-1  |        /ragno/crawler/peering.go:57 +0xd9
ragno-ragno-1 exited with code 2