branching: set build flag to disable before copying and to enable after copying

For a short time during branching the new repository on OBS doesn't have the right settings. i.e. rebuild="local" block="never" and users are not defined during the creation of the new repository (with obs-repository-copy) but only few steps later with obs-prjconf-update.

Thus, to avoid unnecessary rebuilds during this short period of time, we need to disable builds at the beginning of the process and then re-enable at the end of the process.

Signed-off-by: Dylan Aïssi dylan.aissi@collabora.com