Fix refbundle: make it compatible with the new findNstreches script API

snakecnv/referencebundle.snk

@@ -243,8 +243,10 @@ rule nstretches:
         PREFIX+".Nstretch.bed"
     params:
         nstrech =config['maxNstretches']
+    threads:
+        1
     shell:
-        "findNstretches.py -f {input} -m {params.nstrech} > {output}"
+        "findNstretches.py -f {input} -m {params.nstrech} -o {output} -t {threads}"
 
 rule splitchroms:
     input: