build_chroot: install pyinotify inside the chroot
build_chroot: install pyinotify inside the chroot

Commit 0e3f65d2 erroneously installed pyinotify on the host system.
This commit fixes that and adds a comment on why we have to install
this dependency separately in the first place.

Signed-off-by: Santi Raffa <6a214b96de92f36f05379f829a80c82d50682e4c@google.com>
Signed-off-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>
Reviewed-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>

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