docker/collabora: Fix quoting when setting $BIND
When setting BIND="--bind 0.0.0.0:80"
to make the Docker container
listen on the default HTTP port the lack of quoting in the test yields
this message to be printed:
bash: [: --bind: binary operator expected
The flag is then passed correctly to LAVA since the error is triggered only when the test should fail anyway (the variable is not empty), so this is only cosmetic.
Also using BIND="--bind=0.0.0.0:80"
already avoids the issue.