FIX: tag search should not be case sensitive

lib/discourse_tagging.rb

@@ -56,6 +56,7 @@ module DiscourseTagging
   def self.filter_allowed_tags(query, guardian, opts={})
     term = opts[:term]
     if term.present?
+      term.downcase!
       term.gsub!(/[^a-z0-9\.\-\_]*/, '')
       term.gsub!("_", "\\_")
       query = query.where('tags.name like ?', "%#{term}%")