Fix GCC compiler error

[dmikushin]

Fixing the following compiler error on gcc (GCC) 8.5.0 20210514 (RedHat 8.5.0-18):

/root/rpm/plugins/dbus_announce.c:69:5: error: a label can only be part of a statement and a declaration is not a statement
     int ignore = dbus_error_has_name(&err, DBUS_ERROR_NO_SERVER) ||
     ^~~

[pmatilai]

Oh, this "wonderful" quirk of C99. I wonder why newer gcc doesn't complain because I don't think it's legit in C11 either.

Fixed a little differently in 34d983f because I hate the way those locally added blocks mess up the git history (or blame rather), and for full disclosure in the commit log: it's a regression introduced in 071be75.

Thanks for the patch!