Revert "base-files: source functions.sh in /lib/functions/system.sh"

This reverts commit 86aeac4fc9.

The reverted commit introduced a cyclic dependency between
/lib/functions.sh and /lib/functions/system.sh. Further details
are found in 282e817350 ("base-files: do not source system.sh
in functions.sh"), which was applied to master some time ago and
is included in 21.02.

With the current age of 19.07 branch, it seems safer to revert this
mostly cosmetic feature than investing further time into disentangling
the dependencies.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

package/base-files/Makefile

@@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/version.mk
 include $(INCLUDE_DIR)/feeds.mk
 
 PKG_NAME:=base-files
-PKG_RELEASE:=204.3
+PKG_RELEASE:=204.4
 PKG_FLAGS:=nonshared
 
 PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/

package/base-files/files/lib/functions/system.sh

@@ -1,7 +1,5 @@
 # Copyright (C) 2006-2013 OpenWrt.org
 
-. /lib/functions.sh
-
 get_mac_binary() {
 	local path="$1"
 	local offset="$2"