[Minor] Relax CTYPE_MISSING_DISPOSITION rule

rules/headers_checks.lua

@@ -896,6 +896,8 @@ rspamd_config.CTYPE_MISSING_DISPOSITION = {
       if (ct and ct:lower():match('^application/octet%-stream') ~= nil) then
         local cd = p:get_header('Content-Disposition')
         if (not cd) or (cd and cd:lower():find('^attachment') == nil) then
+          local ci = p:get_header('Content-ID')
+          if ci then return false end
           return true
         end
       end
@@ -958,4 +960,4 @@ rspamd_config.INVALID_RCPT_8BIT = {
   description = 'Invalid 8bit character in recipients headers',
   score = 6.0,
   group = 'headers'
-}
+}