wendelin.core: v↑ +py3 build fix

Pick up nexedi/wendelin.core@3d0f134c to
fix build on Python3.

component/wendelin.core/buildout.cfg

@@ -50,7 +50,7 @@ CGO_LDFLAGS += -Wl,-rpath=${zlib:location}/lib
 recipe  = slapos.recipe.build:gitclone
 repository = https://lab.nexedi.com/nexedi/wendelin.core.git
 branch   = master
-revision = wendelin.core-2.0.alpha2-1-gad6305c0
+revision = wendelin.core-2.0.alpha2-2-g3d0f134c
 # dir is pretty name as top-level recipe
 location = ${buildout:parts-directory}/wendelin.core
 git-executable = ${git:location}/bin/git