Merge pull request #961 from m-voloshin/username-editing

Allow user to edit initial username

modules/UI/videolayout/LocalVideo.js

                 $('#localDisplayName').html(
                     `${UIUtil.escapeHtml(displayName)} (${meHTML})`
                 );
+                $('#editDisplayName').val(
+                    `${UIUtil.escapeHtml(displayName)}`
+                );
             } else {
                 $('#localDisplayName').html(defaultLocalDisplayName);
             }