Fix Travis permissions complain

Adding the --privileged option to the `docker run` command.

Read more:

* https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities
* https://github.com/shundhammer/huha-linux-tips/blob/master/doc/yast-devel-tips.md#travis-complains-about-permissions

.travis.yml

@@ -15,4 +15,4 @@ script:
   # The Perl syntax check cannot be used because at the time to call it YCP.pm, which is compiled
   # from YCP.cc, is not available yet.
   # FIXME: enable it after removing pluglib-bindings
-  - docker run -it -e TRAVIS=1 -e TRAVIS_JOB_ID="$TRAVIS_JOB_ID" yast-perl-bindings-image yast-travis-cpp -x perl_syntax
+  - docker run -it --privileged -e TRAVIS=1 -e TRAVIS_JOB_ID="$TRAVIS_JOB_ID" yast-perl-bindings-image yast-travis-cpp -x perl_syntax