Bump xmlrpc from 0.3.3 to 0.3.4

Bumps [xmlrpc](https://github.com/ruby/xmlrpc) from 0.3.3 to 0.3.4.
- [Release notes](https://github.com/ruby/xmlrpc/releases)
- [Changelog](https://github.com/ruby/xmlrpc/blob/master/NEWS.md)
- [Commits](https://github.com/ruby/xmlrpc/compare/v0.3.3...v0.3.4)

---
updated-dependencies:
- dependency-name: xmlrpc
  dependency-version: 0.3.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -759,7 +759,8 @@ GEM
     will_paginate (4.0.1)
     will_paginate-bootstrap-style (0.3.0)
       will_paginate (~> 4.0, >= 4.0.0)
-    xmlrpc (0.3.3)
+    xmlrpc (0.3.4)
+      rexml
       webrick
     xpath (3.2.0)
       nokogiri (~> 1.8)