openbolt-runtime: Add rubygem-rexml component

Author: nmburgan

configs/projects/openbolt-runtime.rb

@@ -196,6 +196,7 @@
   proj.component 'rubygem-ffi'
   proj.component 'rubygem-gssapi'
   proj.component 'rubygem-gyoku'
+  proj.component 'rubygem-rexml'
   proj.component 'rubygem-hiera'
   proj.component 'rubygem-httpclient'
   proj.component 'rubygem-mutex_m'