certs: do not export CA certs in install_pem_from_p12

This fixes `kdc.crt` containing the full chain rather than just the KDC
certificate in CA-less server install.

https://pagure.io/freeipa/issue/6831
https://pagure.io/freeipa/issue/6869

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>

ipaserver/install/certs.py

@@ -64,7 +64,7 @@ def get_cert_nickname(cert):
 
 def install_pem_from_p12(p12_fname, p12_passwd, pem_fname):
     pwd = ipautil.write_tmp_file(p12_passwd)
-    ipautil.run([paths.OPENSSL, "pkcs12", "-nokeys",
+    ipautil.run([paths.OPENSSL, "pkcs12", "-nokeys", "-clcerts",
                  "-in", p12_fname, "-out", pem_fname,
                  "-passin", "file:" + pwd.name])