libevent: Fix install path isn't expected.

component/libevent/buildout.cfg

@@ -9,13 +9,11 @@ configure-options =
   --disable-static
 
 [libevent:cygwin]
-url = ftp://sourceware.org/pub/cygwinports/release-2/libevent/libevent-2.0.21-1-src.tar.bz2
+url = ftp://mirrors.kernel.org/sources.redhat.com/cygwinports/release-2/libevent/libevent-2.0.21-1-src.tar.bz2
 md5sum = dc99127a3e597efebea47a1b6d0e3d7c
 configure-command = cygport
 configure-options =
   libevent.cygport
-  download
   prep
   compile
-  install
-make-binary = true
+make-options = -C libevent-2.0.21-1/build