Quote this to prevent word splitting

https://www.shellcheck.net/wiki/SC2046



Signed-off-by: Dan Callahan <danc@element.io>

When releasing 1.42.0 with @Azrenbeth and talking with @clokep yesterday I realised doing the dch incantations related to releasing Synapse wasn't trivial on eg a macOS system, so this is a script to run in a Debian container to make things a bit easier.