minor cleanup, support for delayed topic creation

package.json

@@ -1,7 +1,7 @@
 {
   "name": "tinode-webapp",
   "description": "Tinode messenger for the web",
-  "version": "0.18.3-beta1",
+  "version": "0.19.0-alpha1",
 
   "repository": {
     "type": "git",
@@ -71,7 +71,7 @@
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
     "react-intl": "^5.20.2",
-    "tinode-sdk": "^0.18.2"
+    "tinode-sdk": "^0.19.0-alpha1"
   },
   "devDependencies": {
     "@babel/core": "^7.14.5",