Fix strange slash

fix slash, generating this error on build in vagrant
==> default: warning: require is a metaparam; this value will inherit to all contained resources
==> default: warning: Unrecognised escape sequence '\ ' in file /tmp/vagrant-puppet-4/modules-0/alfresco/manifests/addons.pp at line 54
==> default: warning: Unrecognised escape sequence '\ ' in file /tmp/vagrant-puppet-4/modules-0/alfresco/manifests/addons.pp at line 55