Wrap line to keep under 100 chars.

Author: yuchenshi

packages/auth/src/auth.js

@@ -301,7 +301,8 @@ fireauth.Auth.prototype.useEmulator = function(url) {
   if (!this.emulatorConfig_) {
     if (!/^https?:\/\//.test(url)) {
       throw new fireauth.AuthError(
-          fireauth.authenum.Error.ARGUMENT_ERROR, 'Emulator URL must start with a valid scheme (http:// or https://).');
+          fireauth.authenum.Error.ARGUMENT_ERROR,
+          'Emulator URL must start with a valid scheme (http:// or https://).');
     }
     // Emit a warning so dev knows we are now in test mode.
     this.emitEmulatorWarning_();