Avoid trying to set uid/gid on windows

lib/puppet/util/suidmanager.rb

@@ -50,7 +50,8 @@ module Puppet::Util::SUIDManager
 
     # Runs block setting uid and gid if provided then restoring original ids
     def asuser(new_uid=nil, new_gid=nil)
-        return yield unless root?
+        return yield if Puppet.features.win32? or !root?
+
         # We set both because some programs like to drop privs, i.e. bash.
         old_uid, old_gid = self.uid, self.gid
         old_euid, old_egid = self.euid, self.egid