Fixes missing local video thumbnail before entering a conference.

modules/UI/UI.js

     if (!interfaceConfig.filmStripOnly) {
         VideoLayout.initLargeVideo(PanelToggler.isVisible());
     }
-    VideoLayout.resizeLargeVideoContainer(PanelToggler.isVisible());
+    VideoLayout.resizeLargeVideoContainer(PanelToggler.isVisible(), true);
 
     ContactList.init(eventEmitter);
 

modules/UI/toolbars/BottomToolbar.js

         return this.filmStrip.width();
     },
 
-    resizeThumbnails (thumbWidth, thumbHeight, animate = false, show = false) {
+    resizeThumbnails (thumbWidth, thumbHeight,
+                      animate = false, forceUpdate = false) {
         return new Promise(resolve => {
             this.filmStrip.animate({
                 // adds 2 px because of small video 1px border
                 duration: animate ? 500 : 0
             });
 
-            this.getThumbs(!show).animate({
+            this.getThumbs(!forceUpdate).animate({
                 height: thumbHeight,
                 width: thumbWidth
             }, {

modules/UI/videolayout/VideoLayout.js

     /**
      * Resizes the large video container.
      */
-    resizeLargeVideoContainer (isSideBarVisible) {
+    resizeLargeVideoContainer (isSideBarVisible, forceUpdate) {
         let animate = false;
         if (largeVideo) {
             largeVideo.updateContainerSize(isSideBarVisible);
             largeVideo.resize(animate);
         }
         this.resizeVideoSpace(animate, isSideBarVisible);
-        this.resizeThumbnails(false);
+        this.resizeThumbnails(false, forceUpdate);
     },
 
     /**
      * Resizes thumbnails.
      */
-    resizeThumbnails (animate = false, show = false) {
+    resizeThumbnails (animate = false, forceUpdate = false) {
         let {thumbWidth, thumbHeight} = this.calculateThumbnailSize();
 
         $('.userAvatar').css('left', (thumbWidth - thumbHeight) / 2);
 
-        BottomToolbar.resizeThumbnails(thumbWidth, thumbHeight, animate, show)
+        BottomToolbar.resizeThumbnails(thumbWidth, thumbHeight,
+            animate, forceUpdate)
             .then(function () {
                 BottomToolbar.resizeToolbar(thumbWidth, thumbHeight);
                 AudioLevels.updateCanvasSize(thumbWidth, thumbHeight);