Maintenance: Update dependency net-imap to v0.4.8

Gemfile.lock

@@ -351,7 +351,7 @@ GEM
       time
     net-http (0.4.0)
       uri
-    net-imap (0.4.7)
+    net-imap (0.4.8)
       date
       net-protocol
     net-ldap (0.18.0)

app/models/channel/driver/imap.rb

@@ -215,10 +215,9 @@ example
     # reverse message order to increase performance
     if check_type == 'verify'
       Rails.logger.info "verify mode, fetch no emails #{verify_string}"
-      message_ids.reverse!
 
       # check for verify message
-      message_ids.each do |message_id|
+      message_ids.reverse_each do |message_id|
 
         message_meta = nil
         timeout(FETCH_METADATA_TIMEOUT) do