Partially revert "Makefile.am: Run pylint on all Python code"
Partially revert "Makefile.am: Run pylint on all Python code"

This partially reverts commit e4e7c7df3a2356103c2442a91d628ca0470fb267,
which made newer pylint versions fail.

Signed-off-by: Michael Hanselmann <68b67885ff74281219b4a4be33cc20fd45078d7c@google.com>
Reviewed-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>

ganeti-github-testing/ganeti-test-1,yiannist/ganeti,apyrgio/snf-ganeti,yiannist/ganeti,andir/ganeti,dimara/ganeti,mbakke/ganeti,leshchevds/ganeti,leshchevds/ganeti,bitemyapp/ganeti,ganeti/ganeti,yiannist/ganeti,apyrgio/ganeti,grnet/snf-ganeti,grnet/snf-ganeti,leshchevds/ganeti,mbakke/ganeti,onponomarev/ganeti,onponomarev/ganeti,ganeti/ganeti,bitemyapp/ganeti,andir/ganeti,mbakke/ganeti,andir/ganeti,apyrgio/snf-ganeti,apyrgio/ganeti,dimara/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti