evensheet fix when no availabilities or positions

src/helpers/eventsheet.js

@@ -88,6 +88,9 @@ const positionGroups = {
 }
 
 exports.positionCapabilityFor = (member, position, options) => {
+  if (!member.position) {
+    return ""
+  }
   const member_positions = member.position.split(",").map(s=>s.trim())
   const member_position_groups = new Set(member.position.split(",").map(s=>positionGroups[s.trim()]))
   
@@ -139,7 +142,7 @@ exports.timepointForMember = (member, timeline, event, options) => {
     value = parsePositionLabel(eventLineupEntry.label).positionLabelWithoutFlags
   }
   else {
-    value = availability.status[0]
+    value = availability?.status[0]
   }
     return options.fn({availability: availability, eventLineupEntry: eventLineupEntry, value}, {data: data })
 }