Correcting link in readme.me

readme.md

@@ -31,8 +31,7 @@ file format defined by the standard ISO/IEC 15909 Part 2.
 See [pnml.org](http://www.pnml.org) for details about this format.
 
 <a name="article"></a> It uses the monotone pruning algorithm proposed in the
-[article](http://pageperso.lif.univ-mrs.fr/~pierre-alain.reynier/publis/
-fi13.pdf):
+[article](http://pageperso.lif.univ-mrs.fr/~pierre-alain.reynier/publis/fi13.pdf):
 
  > Minimal Coverability Set for Petri Nets: Karp and Miller Algorithm with
  > Pruning.