package/go: security bump to version 1.13.7

package/go: security bump to version 1.13.7

Fixes the following security issue:

- Panic in crypto/x509 certificate parsing and golang.org/x/crypto/cryptobyte

On 32-bit architectures, a malformed input to crypto/x509 or the ASN.1
parsing functions of golang.org/x/crypto/cryptobyte can lead to a panic.
The malformed certificate can be delivered via a crypto/tls connection to a
client, or to a server that accepts client certificates.  net/http clients
can be made to crash by an HTTPS server, while net/http servers that accept
client certificates will recover the panic and are unaffected.  Thanks to
Project Wycheproof for providing the test cases that led to the discovery of
this issue.  The issue is CVE-2020-7919 and Go issue golang.org/issue/36837.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>