chore(release): 1.0.0-alpha.52 [skip ci]

# [1.0.0-alpha.52](https://code.podlibre.org/podlibre/castopod/compare/v1.0.0-alpha.51...v1.0.0-alpha.52) (2021-04-16)

### Bug Fixes

* **avatar:** use default avatar when no avatar url has been set ([9d23c7e7](https://code.podlibre.org/podlibre/castopod/commit/9d23c7e7e142c6cf1a1418e37e41d711064593c4)), closes [#111](https://code.podlibre.org/podlibre/castopod/issues/111)