acra: Update to acra-4.5.0 stable.

I had built the previous version from pre-4.5.0 source:
https://github.com/ACRA/acra/commit/414b081ea0c3d577d9f706df109c2d5be55d9da1

Notable change is that reports are deleted from user's device if couch
db rejects them.  Before, they would accumulate on device.  Rejection
can occur if the user is using an older version of mupen.