Initial fix for #61, thanks to herbdool

Suggested by PR 62: #62

Author: twomice

templates/CRM/Activityical/snippet/Feed.tpl

@@ -31,7 +31,7 @@ ORGANIZER:MAILTO:{$activity.contact_email|crmICalText}
 URL:{$activity.url}
 CONTACT;ALTREP={$base_url}/civicrm/contact/view?reset=1&cid={$activity.source_id}:{$activity.source_display_name}
 X-ALT-DESC;FMTTYPE=text/html:
- {$activity.description|activityicalHtml}
+ {$activity.description|crmICalText:true}
 END:VEVENT
 {/foreach}
 END:VCALENDAR