dom0-update: support rpm -K output of rpm 4.14

QubesOS/qubes-issues#4225

dom0-updates/qubes-receive-updates

@@ -41,10 +41,12 @@ package_regex = re.compile(r"^[A-Za-z0-9._+-]{1,128}.rpm$")
 # example valid outputs:
 #  .....rpm: rsa sha1 (md5) pgp md5 OK
 #  .....rpm: (sha1) dsa sha1 md5 gpg OK
+#  .....rpm: digests signatures OK
 # example INVALID outputs:
 #  .....rpm: sha1 md5 OK
 #  .....rpm: RSA sha1 ((MD5) PGP) md5 NOT OK (MISSING KEYS: (MD5) PGP#246110c1)
-gpg_ok_regex = re.compile(r": [a-z0-9() ]* (pgp|gpg) [a-z0-9 ]*OK$")
+#  .....rpm: digests OK
+gpg_ok_regex = re.compile(r": [a-z0-9() ]* (pgp|gpg|signatures) [a-z0-9 ]*OK$")
 
 
 def dom0updates_fatal(pkg, msg):