s3: Add parameter "ctdb timeout"

s3: Add parameter "ctdb timeout"

When something in the cluster blocks, it can happen that we wait indefinitely
long for ctdb, just adding to the blocking condition. In theory, nothing should
block, but as someone said "In practice the difference between theory and
practice is larger than in theory". This adds a timeout parameter in seconds,
after which we stop waiting for ctdb and panic.
(cherry picked from commit 872f59be48e61b0dc874aef72f96a46e8936d86d)