tt-rss: reload-all stops working after newsbeuter has been running a while

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Set urls-source to some "ttrss" instance
2. Start newsbeuter and wait a while
3. Run reload-all

What is the expected output? What do you see instead?
All the feeds are checked for new articles, but none are found. If I close 
newsbeuter and open it again, reload-all works.

What version of the product are you using? On what operating system?
Latest git head (502d08d); tt-rss version: 1.5.5

From a quick look at the code, I suspect that this is happening, because 
ttrss_api::fetch_feed() (among other methods that have same problem) doesn't 
check whether the session id is still valid and hence fails if the session 
expired.

Original issue reported on code.google.com by dan...@schoepe.org on 26 Sep 2011 at 11:36

[GoogleCodeExporter]

I (hopefully) implemented a fix for this:
https://github.com/akrennmair/newsbeuter/pull/14

Original comment by dan...@schoepe.org on 30 Sep 2011 at 8:07