This commit changed the implementation for sending outgoing activities. I believe that it is responsible for major increases in CPU and RAM usage and client errors. Because now there are up to millions of async tasks active which are doing nothing but sleeping, and this likely messes up the scheduler. I will rework this for 0.18.2.

Unfortunately we will get back the problem with HTTP signatures expiring after only 10 seconds, but thats better than overloaded servers. This change needs to go into 0.18.1

This reverts commit d6b580a530563d4a2be76d077e015f9aecc75479.

Originally posted by Nutomic in #3466