Fix buglet introduced in r855.
Fix buglet introduced in r855.

* context.c
  (read_from_connection): return APR_SUCCESS in the case where we're exhausted.


git-svn-id: 683495cb1553624b05a54e2ba9533425f69cf277@856 61a7d7f5-40b7-0310-9c16-bb0ea8cb1845

coapp-packages/serf,coapp-packages/serf,coapp-packages/serf