Return correct promise in error case

package.json

@@ -1,7 +1,7 @@
 {
   "name": "openpgp",
   "description": "OpenPGP.js is a Javascript implementation of the OpenPGP protocol. This is defined in RFC 4880.",
-  "version": "0.8.1-dev",
+  "version": "0.8.1",
   "homepage": "http://openpgpjs.org/",
   "engines": {
     "node": ">=0.8"

src/openpgp.js

@@ -278,9 +278,7 @@ function execute(cmd, errMsg) {
   });
 
   // handler error globally
-  promise.catch(onError.bind(null, errMsg));
-
-  return promise;
+  return promise.catch(onError.bind(null, errMsg));
 }
 
 /**