Bump net-imap from 0.4.5 to 0.4.6

Bumps [net-imap](https://github.com/ruby/net-imap) from 0.4.5 to 0.4.6.
- [Release notes](https://github.com/ruby/net-imap/releases)
- [Commits](https://github.com/ruby/net-imap/compare/v0.4.5...v0.4.6)

---
updated-dependencies:
- dependency-name: net-imap
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -256,7 +256,7 @@ GEM
     nested_form (0.3.2)
     net-http-persistent (4.0.2)
       connection_pool (~> 2.2)
-    net-imap (0.4.5)
+    net-imap (0.4.6)
       date
       net-protocol
     net-pop (0.1.2)