support/download: fix shellcheck errors in svn backend
Bizarrely enough, the unquoted expansion of ${quiet} does not trigger
any warning from shellcheck, so we do not add any exception for it.
${SVN} can contain more than one item, but we don't care about splitting
on spaces when we just print it for debug, so we can just quote it
rather than add an exception.
Signed-off-by: Yann E. MORIN <yann.morin@orange.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>