[R] add Requires: qpdf to R-core-devel

[Tom Callaway]

commit 86e5628e852034cbe8fa3059aa2d1eca5e61b33d
Author: Tom Callaway <spot at fedoraproject.org>
Date:   Fri Jan 2 16:29:56 2015 -0500

    add Requires: qpdf to R-core-devel

 R.spec |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/R.spec b/R.spec
index 98a386d..a2f73e5 100644
--- a/R.spec
+++ b/R.spec
@@ -199,6 +199,9 @@ Requires: tex(ptmri8t.tfm)
 Requires: tex(ptmro8t.tfm)
 Requires: tex(cm-super-ts1.enc)
 %endif
+# "‘qpdf’ is needed for checks on size reduction of PDFs"
+Requires: qpdf
+
 Provides: R-Matrix-devel = 1.1.4
 Obsoletes: R-Matrix-devel < 0.999375-7