api: fix broken support for 'baseline' parameter
api: fix broken support for 'baseline' parameter

/builds/<id>/email and /builds/<id>/report APIs should support
'baseline' parameter. This patch fixes the features. Before baseline was
always set to None.

Signed-off-by: Milosz Wasilewski <a39812e55748be210556797addcf4c064734f1bf@linaro.org>

terceiro/squad,terceiro/squad,terceiro/squad,terceiro/squad