Add missing dependency on host python.

Author: mkhon

Makefile

@@ -167,7 +167,7 @@ $$(OPENSSL_DIR-$1)/libssl.a $$(OPENSSL_DIR-$1)/libcrypto.a: $$(OPENSSL_DIR-$1)/M
 		make all
 
 # Unpack Python
-$$(PYTHON_DIR-$1)/Makefile: downloads/Python-$(PYTHON_VERSION).tgz
+$$(PYTHON_DIR-$1)/Makefile: downloads/Python-$(PYTHON_VERSION).tgz Python-host
 	# Unpack target Python
 	mkdir -p $$(PYTHON_DIR-$1)
 	tar zxf downloads/Python-$(PYTHON_VERSION).tgz --strip-components 1 -C $$(PYTHON_DIR-$1)