Some issues found with type checking, fixes #4429

lib/sidekiq/logger.rb

@@ -83,7 +83,7 @@ module Sidekiq
     # Redefined to check severity against #level, and thus the thread-local level, rather than +@level+.
     # FIXME: Remove when the minimum Ruby version supports overriding Logger#level.
     def add(severity, message = nil, progname = nil, &block)
-      severity ||= UNKNOWN
+      severity ||= ::Logger::UNKNOWN
       progname ||= @progname
 
       return true if @logdev.nil? || severity < level

lib/sidekiq/processor.rb

@@ -181,7 +181,7 @@ module Sidekiq
         # the retry subsystem (e.g. network partition).  We won't acknowledge the job
         # so it can be rescued when using Sidekiq Pro.
         handle_exception(ex, {context: "Internal exception!", job: job_hash, jobstr: jobstr})
-        raise e
+        raise ex
       ensure
         if ack
           # We don't want a shutdown signal to interrupt job acknowledgment.