refs #80: fixes wrong problem link.

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

lib/config.js

@@ -7,7 +7,8 @@ var DEFAULT_SYS_CONFIG = {
   URL_BASE:            'https://leetcode.com',
   URL_LOGIN:           'https://leetcode.com/accounts/login/',
   URL_PROBLEMS:        'https://leetcode.com/api/problems/$category/',
-  URL_PROBLEM:         'https://leetcode.com/graphql',
+  URL_PROBLEM:         'https://leetcode.com/problems/$slug/description/',
+  URL_PROBLEM_DETAIL:  'https://leetcode.com/graphql',
   URL_TEST:            'https://leetcode.com/problems/$slug/interpret_solution/',
   URL_SUBMIT:          'https://leetcode.com/problems/$slug/submit/',
   URL_SUBMISSIONS:     'https://leetcode.com/api/submissions/$slug',

lib/plugins/leetcode.js

@@ -117,7 +117,7 @@ plugin.getProblem = function(problem, cb) {
   var user = session.getUser();
   if (problem.locked && !user.paid) return cb('failed to load locked problem!');
 
-  var opts = makeOpts(config.URL_PROBLEM);
+  var opts = makeOpts(config.URL_PROBLEM_DETAIL);
   opts.headers.Origin = config.URL_BASE;
   opts.headers.Referer = problem.link;