rescue from all exceptions in `ConnectionManagement#call`

Fixes #11497

As `ActiveRecord::ConnectionAdapters::ConnectionManagement` middleware does not rescue from Exception (but only from StandardError),
the Connection Pool quickly runs out of connections when multiple erroneous Requests come in right after each other.

Recueing from all exceptions and not just StandardError, fixes this behaviour.
Merge pull request #11538 from vipulnsward/rescue-exp

rescue from all exceptions in `ConnectionManagement#call`