change docker repo

recipes/peakcallers/macs2/Singularity.macs2-2271

 Bootstrap: docker
-From: biocontainers/macs2:2.2.7.1--py39hbf8eff0_4
+From: dceoy/macs2:latest
 
 %runscript
-    echo "Running container biocontainers/macs2:2.2.7.1--py39hbf8eff0_4, macs2 v2.2.7.1"
+    echo "Running container dceoy/macs2, macs2 v2.2.7.1"
     exec /bin/bash "$@"
 
 %post
     mkdir /cluster /work /tsd /projects
-
-%labels
-    Author Nicolas Descostes