TBR Bump extension to v0.1.19

This keeps our extension's wsprd up-to-date with the recent
identity changes.

Change-Id: I251532f2febda58d1248d81e71e66dd40c9a8fd5
diff --git a/extension/manifest.json b/extension/manifest.json
index ff4779b..a6d7465 100644
--- a/extension/manifest.json
+++ b/extension/manifest.json
@@ -1,6 +1,6 @@
 {
   "name": "Vanadium Extension",
-  "version": "0.1.18",
+  "version": "0.1.19",
   "description": "Access and create Vanadium services from JavaScript.",
   "manifest_version": 2,
   "icons": {