remove the EncryptionUnspecified enum value

internal/protocol/encryption_level_test.go

@@ -6,8 +6,12 @@ import (
 )
 
 var _ = Describe("Encryption Level", func() {
+	It("doesn't use 0 as a value", func() {
+		// 0 is used in some tests
+		Expect(EncryptionInitial * EncryptionHandshake * Encryption0RTT * Encryption1RTT).ToNot(BeZero())
+	})
+
 	It("has the correct string representation", func() {
-		Expect(EncryptionUnspecified.String()).To(Equal("unknown"))
 		Expect(EncryptionInitial.String()).To(Equal("Initial"))
 		Expect(EncryptionHandshake.String()).To(Equal("Handshake"))
 		Expect(Encryption0RTT.String()).To(Equal("0-RTT"))