fixed renaming missing callback (#28)

services/spelling/app/js/ASpell.js

@@ -39,8 +39,13 @@ setInterval(function() {
       logger.log({ err }, 'error writing cache file')
       return fs.unlink(cacheFsPathTmp)
     } else {
-      fs.rename(cacheFsPathTmp, cacheFsPath)
-      return logger.log({ len: dump.length, cacheFsPath }, 'wrote cache file')
+      fs.rename(cacheFsPathTmp, cacheFsPath, err => {
+        if (err) {
+          logger.error({ err }, 'error renaming cache file')
+        } else {
+          logger.log({ len: dump.length, cacheFsPath }, 'wrote cache file')
+        }
+      })
     }
   })
 }, 30 * OneMinute)