old_contents: import hashlib
  import urllib.parse
  
  from django import template
  
  
  register = template.Library()
  
  
  @register.filter
  def gravatarize(value):
      h = hashlib.md5(value.lower().encode('utf-8')).hexdigest()
      gravatar_url = "http://www.gravatar.com/avatar/" + h + "?"
      return gravatar_url + urllib.parse.urlencode({
          'd': 'avatar@calltospeakers.com',
          's': 50,
      })
  
new_contents: import hashlib
  import urllib.parse
  
  from django import template
  
  
  register = template.Library()
  
  
  @register.filter
  def gravatarize(value):
      h = hashlib.md5(value.lower().encode('utf-8')).hexdigest()
      gravatar_url = "https://www.gravatar.com/avatar/" + h + "?"
      return gravatar_url + urllib.parse.urlencode({
          'd': 'avatar@calltospeakers.com',
          's': 50,
      })
  
subject: Use SSL for gravatar