refs #174 Skip removeEvents when dom does not have a target element

src/renderer/components/TimelineSpace/Contents/Favourites.vue

@@ -45,7 +45,9 @@ export default {
     document.getElementById('scrollable').addEventListener('scroll', this.onScroll)
   },
   destroyed () {
-    document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    if (document.getElementById('scrollable') !== undefined && document.getElementById('scrollable') !== null) {
+      document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    }
   },
   methods: {
     updateToot (message) {

src/renderer/components/TimelineSpace/Contents/Home.vue

@@ -32,7 +32,9 @@ export default {
   },
   destroyed () {
     this.$store.commit('TimelineSpace/archiveHomeTimeline')
-    document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    if (document.getElementById('scrollable') !== undefined && document.getElementById('scrollable') !== null) {
+      document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    }
   },
   methods: {
     onScroll (event) {

src/renderer/components/TimelineSpace/Contents/Local.vue

@@ -41,7 +41,9 @@ export default {
     this.$store.dispatch('TimelineSpace/Contents/Local/stopLocalStreaming')
   },
   destroyed () {
-    document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    if (document.getElementById('scrollable') !== undefined && document.getElementById('scrollable') !== null) {
+      document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    }
   },
   methods: {
     async initialize () {

src/renderer/components/TimelineSpace/Contents/Notifications.vue

@@ -32,7 +32,9 @@ export default {
   },
   destroyed () {
     this.$store.commit('TimelineSpace/archiveNotifications')
-    document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    if (document.getElementById('scrollable') !== undefined && document.getElementById('scrollable') !== null) {
+      document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    }
   },
   methods: {
     onScroll (event) {

src/renderer/components/TimelineSpace/Contents/Public.vue

@@ -41,7 +41,9 @@ export default {
     this.$store.dispatch('TimelineSpace/Contents/Public/stopPublicStreaming')
   },
   destroyed () {
-    document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    if (document.getElementById('scrollable') !== undefined && document.getElementById('scrollable') !== null) {
+      document.getElementById('scrollable').removeEventListener('scroll', this.onScroll)
+    }
   },
   methods: {
     async initialize () {