[rubygem-narray] RHEL <= 6 needs to have an arched devel-pkg, because of misallignments in %doc

[Björn 'besser82' Esser]

Summary of changes:

  d347476... RHEL <= 6 needs to have an arched devel-pkg, because of mis (*)

(*) This commit already existed in another branch; no separate mail sent