Fixed #1052 - connection in Router.change(ChangeEvent) is critical section
Fixed #1052 - connection in Router.change(ChangeEvent) is critical section

In case of `/_changes` with longpoll, the connection is critical section when multiple threads write document simultaneously. Synchronized block of critical section.

4u7/couchbase-lite-java-core,gotmyjobs/couchbase-lite-java-core,couchbase/couchbase-lite-java-core