debian builds not actively maintained, so suppress error in setup script

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@164 f882894a-f735-0410-b71e-b25c423dba1c

tools/setup

@@ -5,4 +5,6 @@ automake
 autoheader
 autoconf
 
-chmod +x debian/rules
+if [ -f debian/rules ] ; then
+  chmod +x debian/rules
+fi