[rpmbuild] correct the nosync.i686 requirement

Per dnf report:
Problem: cannot install the best candidate for the job
- nothing provides nosync.i686 needed by copr-builder-0.26.git.1.c5bb33f4-1.fc31.x86_64

The 'nosync.i686' is actually yum/dnf construct, not a real
provide to depend on.

rpmbuild/copr-rpmbuild.spec

@@ -100,7 +100,7 @@ Requires: libsemanage-python
 Requires: nosync
 %ifarch x86_64
 # multilib counterpart to avoid: config_opts['nosync_force'] = True
-Requires: nosync.i686
+Requires: nosync(x86-32)
 %endif
 Requires: openssh-clients
 Requires: pyp2rpm