Follow-up to r1982. Remove SERF_HAS_SSL_SESSION_API macro.
Follow-up to r1982. Remove SERF_HAS_SSL_SESSION_API macro.

* serf_bucket_types.h
  (SERF_HAS_SSL_SESSION_API): Remove.

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