contrib: don't include config.h in installed pthread.h

It's retarded for an installed file to depend on it

extras/contrib/src/contrib-src.mak

@@ -2303,7 +2303,7 @@ ifdef HAVE_WIN64
 endif
 
 .pthreads: pthreads
-	(cd $<; $(HOSTCC) $(PTHREADSCONF) make MAKEFLAGS=-j1 GC GC-static && mkdir -p $(PREFIX)/include && cp -v pthread.h sched.h semaphore.h $(PREFIX)/include/ && mkdir -p $(PREFIX)/lib && cp -v *.a *.dll $(PREFIX)/lib/)
+	(cd $<; $(HOSTCC) $(PTHREADSCONF) make MAKEFLAGS=-j1 GC GC-static && mkdir -p $(PREFIX)/include && cp -v pthread.h sched.h semaphore.h $(PREFIX)/include/ && sed -i 's/#if HAVE_CONFIG_H/#if 0 \&\& HAVE_CONFIG_H/' $(PREFIX)/include/pthread.h && mkdir -p $(PREFIX)/lib && cp -v *.a *.dll $(PREFIX)/lib/)
 	$(INSTALL_NAME)
 	touch $@