Fix lint warnings and turn warnings back on (#7409)

Signed-off-by: Aaron Raimist <aaron@raim.ist>

src/vector/index.js

@@ -60,10 +60,6 @@ import CallHandler from 'matrix-react-sdk/lib/CallHandler';
 
 import {getVectorConfig} from './getconfig';
 
-// Disable warnings for now: we use deprecated bluebird functions
-// and need to migrate, but they spam the console with warnings.
-Promise.config({warnings: false});
-
 let lastLocationHashSet = null;
 
 function initRageshake() {
@@ -205,9 +201,9 @@ function getConfig(configJsonFilename) {
                 // which breaks if there's no config.json and we're
                 // loading from the filesystem (see above).
                 resolve(JSON.parse(body));
-            }
+            },
         );
-    })
+    });
 }
 
 function onTokenLoginCompleted() {