Upgrading server dependancies (#4566)

vendor/github.com/miekg/dns/dnssec_keyscan.go

@@ -14,7 +14,7 @@ import (
 // NewPrivateKey returns a PrivateKey by parsing the string s.
 // s should be in the same form of the BIND private key files.
 func (k *DNSKEY) NewPrivateKey(s string) (crypto.PrivateKey, error) {
-	if s[len(s)-1] != '\n' { // We need a closing newline
+	if s == "" || s[len(s)-1] != '\n' { // We need a closing newline
 		return k.ReadPrivateKey(strings.NewReader(s+"\n"), "")
 	}
 	return k.ReadPrivateKey(strings.NewReader(s), "")