gluon-core: ensure the release file is always up-to-date

package/gluon-core/Makefile

@@ -27,7 +27,6 @@ define Build/Configure
 endef
 
 define Build/Compile
-	echo "$(GLUON_RELEASE)" > $(PKG_BUILD_DIR)/release
 endef
 
 define Package/gluon-core/install
@@ -35,7 +34,7 @@ define Package/gluon-core/install
 	$(GLUON_GENERATE) ./generate/* $(1)/
 
 	$(INSTALL_DIR) $(1)/lib/gluon
-	$(INSTALL_DATA) $(PKG_BUILD_DIR)/release $(1)/lib/gluon/release
+	echo "$(GLUON_RELEASE)" > $(1)/lib/gluon/release
 endef
 
 $(eval $(call BuildPackage,gluon-core))