Remove auth_enc config option

As we didn't hear any voices requesting this feature, we removed the
option to disable it and always have peer connection auth encrypted.

closes #1518
follow-up #1325

config/config.go

@@ -287,9 +287,6 @@ type P2PConfig struct {
 	// Does not work if the peer-exchange reactor is disabled.
 	SeedMode bool `mapstructure:"seed_mode"`
 
-	// Authenticated encryption
-	AuthEnc bool `mapstructure:"auth_enc"`
-
 	// Comma separated list of peer IDs to keep private (will not be gossiped to other peers)
 	PrivatePeerIDs string `mapstructure:"private_peer_ids"`
 
@@ -310,7 +307,6 @@ func DefaultP2PConfig() *P2PConfig {
 		RecvRate:                512000, // 500 kB/s
 		PexReactor:              true,
 		SeedMode:                false,
-		AuthEnc:                 true,
 		AllowDuplicateIP:        true, // so non-breaking yet
 	}
 }

config/toml.go

@@ -165,9 +165,6 @@ pex = {{ .P2P.PexReactor }}
 # Does not work if the peer-exchange reactor is disabled.
 seed_mode = {{ .P2P.SeedMode }}
 
-# Authenticated encryption
-auth_enc = {{ .P2P.AuthEnc }}
-
 # Comma separated list of peer IDs to keep private (will not be gossiped to other peers)
 private_peer_ids = "{{ .P2P.PrivatePeerIDs }}"