Follow up to r2055: Fix segfault in the test suite.
Follow up to r2055: Fix segfault in the test suite.

* test/server/test_server.c
  (proxy_replay): Create servctx->servstream when needed.

x-clone/serf,x-clone/serf,KyleSanderson/serf,google-code-export/serf,alex1818/serf,SirJson/serf,zhupan/serf,yesoce/serf,pengdu/serf,alex1818/serf,zhupan/serf,zhengcq315/serf,pengdu/serf,zhengcq315/serf,google-code-export/serf,zhengcq315/serf,soufianeEL/serf,KyleSanderson/serf,google-code-export/serf,SirJson/serf,KyleSanderson/serf,yesoce/serf,pengdu/serf,stoneCC/serf,stoneCC/serf,google-code-export/serf,zhupan/serf,SirJson/serf,stoneCC/serf,SirJson/serf,zhengcq315/serf,stoneCC/serf,soufianeEL/serf,soufianeEL/serf,alex1818/serf,pengdu/serf,lazysoez/serf,yesoce/serf,KyleSanderson/serf,alex1818/serf,yesoce/serf,zhupan/serf,lazysoez/serf,x-clone/serf,x-clone/serf,lazysoez/serf,soufianeEL/serf,lazysoez/serf