Follow up to r2203, value returned by serf_get_config_string is now a const *.
Follow up to r2203, value returned by serf_get_config_string is now a const *.

* test/test_internal.c
  (test_config_store_per_context,
   test_config_store_per_connection_different_host,
   test_config_store_per_connection_same_host): Make actual variables a 
       const char *.

wzugang/serf,TommyU/serf,TommyU/serf,sworda/serf,sworda/serf,Manouchehri/serf,liuzongquan/serf,krime/serf,Manouchehri/serf,blueszhangsh/serf,muthusuba/serf,krime/serf,blueszhangsh/serf,blueszhangsh/serf,Manouchehri/serf,idomon/serf,muthusuba/serf,idomon/serf,wzugang/serf,TommyU/serf,justinweb/serf,justinweb/serf,idomon/serf,muthusuba/serf,wzugang/serf,liuzongquan/serf,blueszhangsh/serf,idomon/serf,TommyU/serf,Manouchehri/serf,liuzongquan/serf,justinweb/serf,liuzongquan/serf,krime/serf,muthusuba/serf,sworda/serf,sworda/serf,wzugang/serf,krime/serf,justinweb/serf