letsencrypt: use salt['pillar.get']

letsencrypt/files/cli.ini.j2

 # account
-agree-tos = {{ pillar.letsencrypt.agree_tos | default(False) }}
-email = {{ pillar.letsencrypt.email }}
+agree-tos = {{ salt['pillar.get']('letsencrypt:agree_tos', False) }}
+email = {{ salt['pillar.get']('letsencrypt:email') }}
 
 # certificates
-rsa-key-size = {{ pillar.letsencrypt.key_size | default(4096) }}
+rsa-key-size = {{ salt['pillar.get']('letsencrypt:key_size', 4096) }}
 
 # webroot challenge
 authenticator = webroot
-webroot-path = {{ pillar.letsencrypt.webroot_path }}
+webroot-path = {{ salt['pillar.get']('letsencrypt:webroot_path') }}