tests: Use more deterministic error message in TestEtcdPeerNameAuth

tests/e2e/etcd_config_test.go

@@ -260,7 +260,7 @@ func TestEtcdPeerNameAuth(t *testing.T) {
 		if i <= 1 {
 			expect = etcdServerReadyLines
 		} else {
-			expect = []string{"remote error: tls: bad certificate"}
+			expect = []string{"client certificate authentication failed"}
 		}
 		if err := waitReadyExpectProc(p, expect); err != nil {
 			t.Fatal(err)