Fix build

This fixes this build failure:

error TS18003: No inputs were found in config file '/home/davido/.cache/bazel/_bazel_davido/496771e6fd159c87df977b2e99ede97d/execroot/gerrit/plugins/reviewers/tsconfig.json'. Specified 'include' paths were '["plugins/reviewers/web/**/*"]' and 'exclude' paths were '[]'.

ERROR: /home/davido/projects/gerrit3/plugins/reviewers/BUILD:32:11: output 'plugins/reviewers/web/plugin.js' was not created

Change-Id: I7a5fae0a3db655ee9a683cc9d2da6984b4cc2325
diff --git a/tsconfig.json b/tsconfig.json
index a9d186e..e1d5137 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,6 @@
 {
   "extends": "../tsconfig-plugins-base.json",
   "include": [
-    "web/**/*",
+    "web/**/*.ts",
   ]
 }