Revert "disable _gsskrb5_pname_to_uid, there's no aname_to_localname"

This reverts commit ad69ac97b1.

lib/gssapi/krb5/pname_to_uid.c

@@ -38,7 +38,6 @@ _gsskrb5_pname_to_uid(OM_uint32 *minor_status,
                       const gss_OID mech_type,
                       uid_t *uidp) 
 {
-#if 0
     krb5_error_code ret;
     krb5_context context;
     krb5_const_principal princ = (krb5_const_principal)pname;
@@ -78,8 +77,4 @@ _gsskrb5_pname_to_uid(OM_uint32 *minor_status,
     *uidp = pwd->pw_uid;
 
     return GSS_S_COMPLETE;
-#else
-    *minor_status = KRB5_NO_LOCALNAME;
-    return GSS_S_UNAVAILABLE;
-#endif
 }