Failed login call might break resuming a session

[bratelefant]

In User.js, in the _loginWithToken method, right before calling the servers login method, the flag this._isCallingLogin is set. Subsequent calls of _loginWithToken will not execute a login request to the server.

meteor-react-native/src/user/User.js

Line 197 in f3222c7

if (this._isCallingLogin) {

Although this helps to prevent sending unnecessary multiple requests, there's a problem in the following situation (observed multiple times in production): If, for some reason, the login request does not finish (connection broken, timeouts, etc), the app remains in the state where this._isCallingLogin === true; hence, any further attempts to resume the user session will fail.