BUG/MINOR: tools: make str2sa_range() report unresolvable addresses

If an environment variable is used in an address, and is not set, it's
silently considered as ":" or "0.0.0.0:0" which is not correct as it
can hide environment issues and lead to unexpected behaviours. Let's
report this case when it happens.

This fix should be backported to 1.5.
1 file changed