python-gnupg: Fix build breakage

Apparently := doesn't work here. Why it doesn't should be investigated but for now fix it.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

lang/python/python-gnupg/Makefile

@@ -6,7 +6,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=python-gnupg
 PKG_VERSION:=0.4.3
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://files.pythonhosted.org/packages/source/p/python-gnupg
@@ -17,7 +17,7 @@ PKG_LICENSE_FILES:=LICENSE
 PKG_MAINTAINER:=Daniel Golle <daniel@makrotopia.org>
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(BUILD_VARIANT)-$(PKG_NAME)-$(PKG_VERSION)
-PKG_UNPACK:=$(HOST_TAR) -C $(PKG_BUILD_DIR) --strip-components=1 -xzf $(DL_DIR)/$(PKG_SOURCE)
+PKG_UNPACK=$(HOST_TAR) -C $(PKG_BUILD_DIR) --strip-components=1 -xzf $(DL_DIR)/$(PKG_SOURCE)
 
 include $(INCLUDE_DIR)/package.mk
 include ../python-package.mk