Minor - Plugins: Zoom - Fix URL, show error message

BT#17288

plugin/zoom/lib/ZoomPlugin.php

@@ -1220,11 +1220,13 @@ class ZoomPlugin extends Plugin
                     //if ('true' === $this->get('enableParticipantRegistration') && $meeting->requiresRegistration()) {
                     // the participant must be registered
                     $registrant = $meeting->getRegistrant($currentUser);
-                    if (null !== $registrant) {
+                    if (null == $registrant) {
+                        throw new Exception($this->get_lang('YouAreNotRegisteredToThisMeeting'));
+                    }
+
                     // the participant is registered
                     return $registrant->getCreatedRegistration()->join_url;
                 }
-                }
                 break;
         }
 

plugin/zoom/view/meeting.tpl

@@ -36,7 +36,7 @@
                     <input id="share_button_flash" type="text"
                            style="width:460px"
                            class="form-control" readonly
-                           value="{{ _p.web_main }}plugin/zoom/join_meeting.php?meetingId={{ meeting.meetingId }}&{{ url_extra }}"
+                           value="{{ _p.web }}plugin/zoom/join_meeting.php?meetingId={{ meeting.meetingId }}&{{ url_extra }}"
                     >
                     <button onclick="copyTextToClipBoard('share_button_flash');" class="btn btn-default">
                         <span class="fa fa-copy"></span> {{ 'CopyTextToClipboard' | get_lang }}