fix if prop undefined for getMxc and event

src/components/event.vue

@@ -1,7 +1,7 @@
 <template>
   <div class="event">
     <div v-if="event.type==='m.room.message'" :class="type==='send'?'messageSend':'messageReceive'" class="message">
-      <reply-event :event="replyEvent"/>
+      <reply-event :event="replyEvent" v-if="replyEvent"/>
 
       <div v-if="event.content.msgtype==='m.text'" v-html="parseMessage(event.content.body)"/>
       <div v-else-if="event.content.msgtype==='m.notice'" class="notice" v-html="parseMessage(event.content.body)"/>

src/lib/getMxc.js

@@ -26,6 +26,7 @@ export function getPreviewUrl(mxcUrl, size = 64, resizeMethod = 'crop'){
 }
 
 export function getMediaUrl(mxcUrl){
+  if (!mxcUrl) return undefined;
   let mxc = parseMXC.parse(mxcUrl);
   return `${matrix.baseUrl}/_matrix/media/r0/download/${
     mxc.homeserver}/${mxc.id}`;