Strip before passing to addressable, otherwise it's invalid

lib/banzai/filter/sanitization_filter.rb

@@ -73,8 +73,9 @@ module Banzai
             return unless node.has_attribute?('href')
 
             begin
+              node['href'] = node['href'].strip
               uri = Addressable::URI.parse(node['href'])
-              uri.scheme = uri.scheme.strip.downcase if uri.scheme
+              uri.scheme = uri.scheme.downcase if uri.scheme
 
               node.remove_attribute('href') if UNSAFE_PROTOCOLS.include?(uri.scheme)
             rescue Addressable::URI::InvalidURIError