xacro: 1.9.2-0 in 'indigo/distribution.yaml' [bloom]

Increasing version of package(s) in repository `xacro` to `1.9.2-0`:

- distro file: `indigo/distribution.yaml`
- bloom version: `0.5.10`
- previous version for package: `1.9.1-0`

## xacro

```
* add a few more tests to exercise the symbol table a bit more
* allow for recursive evaluation of properties in expressions
* add useful debugging information when parameters are not set
* stop test from failing the second time it is run
* unified if/unless handling, correctly handle floating point expressions
* floating point expressions not equal zero are now evaluated as True
* changed quotes to omit cmake warning
* Contributors: Robert Haschke, Mike Ferguson
```