acme/autocert: correct typo in comments

Author: aofei

acme/autocert/autocert.go

@@ -252,11 +252,10 @@ func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate,
 	}
 
 	// Note that this conversion is necessary because some server names in the handshakes
-	// made by some clients (like cURL) is not implicitly converted to Punycode, which will
-	// cause the certificate to fail to be obtained. In addition, we should also treat
-	// example.com and EXAMPLE.COM as equivalent and must return the same certificate for
-	// them. Fortunately, this conversion also helped us deal with this kind of mixedcase
-	// problems.
+	// started by some clients (like cURL) are not implicitly converted to Punycode, which
+	// will cause the certificate to fail to be obtained. In addition, we should also treat
+	// example.com and EXAMPLE.COM as equivalent and return the same certificate for them.
+	// Fortunately, this conversion also helped us deal with this kind of mixedcase problems.
 	//
 	// Due to the "σςΣ" problem (see https://unicode.org/faq/idn.html#22), we can't use
 	// idna.Punycode.ToASCII (or just idna.ToASCII) here.