[perl-Math-Random-ISAAC] Only use %%license when it exists

[Emmanuel Seyman]

commit b0914f6ae694b2e081e7c37e76321fe1c0963a61
Author: Emmanuel Seyman <emmanuel at seyman.fr>
Date:   Sun Sep 21 10:19:12 2014 +0200

    Only use %%license when it exists

 perl-Math-Random-ISAAC.spec |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/perl-Math-Random-ISAAC.spec b/perl-Math-Random-ISAAC.spec
index 0d709fb..c4c0ac0 100644
--- a/perl-Math-Random-ISAAC.spec
+++ b/perl-Math-Random-ISAAC.spec
@@ -41,6 +41,7 @@ make test
 
 %files
 %doc Changes examples README
+%{!?_licensedir:%global license %%doc}
 %license LICENSE
 %{perl_vendorlib}/*
 %{_mandir}/man3/*