proto/zeromq: Don't leak ub on write error in uwsgi_proto_zeromq_writev_header

Reported by Coverity as CID #971247.
plugins/http: fixup some leaks in spdy

Reported by Coverity as CID #971245, #971246.
Merge pull request #143 from xrmx/coverity6

Fix some leaks reported by Coverity scan
announce only spdy3
better route/sendfile/offload logging
improved sendfile management
offloading by default, if available
fixed backlog reporting on 32bit
fixed SERVER_PORT in routers when shared sockets are in place
added --thunder-lock
fixed PTHREAD_PRIO_INHERIT
better support for robust mutexes
added --static-gzip-* options
improved alarm_xmpp plugin