do not make the filesystem of the container writable
We do not need to have the container file system writable. It's enough that bind paths are mounted in read/write mode.
It also fixes the execution (in the new nightlies) of the XMLSummaryKernel.writeerror
test in LHCb
which relies on the fact that the test can't write to /
, AFAIU.
Edited by Maciej Pawel Szymanski