Add default "else" branch to the conditional router

[mrm1001]

When adding a conditional router with many branching options, it would be good to have an easy way to define a default "catch-all" branch in case the other conditions are not met. In other words, would it be possible to reproduce the following logic with a conditional router:

if [condition 1]: branch 1
if [condition 2]: branch 2
else: branch 3