Revert "Merge branch 'fix_15671' into 'master'"

This reverts merge request !811 (merged) because it has some side effects on Nancy and Lyon.

lib/refrepo/valid/network.rb

@@ -285,7 +285,6 @@ def generate_dot(netnodes, links, site)
   mynetnodes = []
   netnodes.each do |n|
     next if n['interface'] == 'InfiniBand' or n['interface'] == 'Myrinet' or hpc_switch?(n)
-    next if n['found'] == 1 and n['kind'] == 'switch' # we remove switches which has only on link
     mynetnodes << n
   end
   # delete nodes we don't care about (HPC networks)