Fix perl-threads dependency on the interpreter API

There was an one-line mistake in the following comit. The dependency
on perl's name-version without release number could never been
satisfied.

commit fde8b38ed3
Author: Marcela Mašláňová <mmaslano@redhat.com>
Date:   Mon Aug 13 14:05:08 2012 +0200

    Define perl_compat by macro for rebuilds.

    Sub-packages depend on compat rather than on nvr.

perl.spec

@@ -2656,7 +2656,7 @@ Group:          Development/Libraries
 License:        GPL+ or Artistic
 Epoch:          1
 Version:        2.07
-Requires:       perl = %{perl_epoch}:%{perl_version}
+Requires:       %perl_compat
 %if %{defined perl_bootstrap}
 %gendep_perl_threads
 %endif