Don't allow installing packages without ARCH or OS

We had an exception for public key packages in rpmte. With those now
being handled in the keystore without going through the transaction
machinery this is no longer needed. This also prevents people from just
contrsucting their own pubkey packages and install them.

Resolves: rpm-software-management#3344

lib/rpmte.cc

@@ -159,8 +159,7 @@ static int addTE(rpmte p, Header h, fnpyKey key, rpmRelocation * relocs)
     p->arch = headerGetAsString(h, RPMTAG_ARCH);
     p->os = headerGetAsString(h, RPMTAG_OS);
 
-    /* gpg-pubkey's dont have os or arch (sigh), for others they are required */
-    if (!rstreq(p->name, "gpg-pubkey") && (p->arch == NULL || p->os == NULL))
+    if (p->arch == NULL || p->os == NULL)
 	goto exit;
 
     p->isSource = headerIsSource(h);