package/sudo: fix SUDO_ENABLE_SUDO_GROUP_RULE following version bump

Since the version bump of sudo to v1.9.11p2 in commit 9b7f8da96b, the
sed magic in SUDO_ENABLE_SUDO_GROUP_RULE no longer does its job, due
to a slight change in the example sudoers file provided by upstream
sudo.

This commit fixes the regexp to match the new sudoers file.

Fixes bug #14891 (https://bugs.busybox.net/show_bug.cgi?id=14891)

Reported-by: Matthias Hardt <mhardt@berlinux-solutions.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 079fccdee5a2a10fc8275094512b8423548ea147)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/sudo/sudo.mk

@@ -82,7 +82,7 @@ define SUDO_USERS
 endef
 
 define SUDO_ENABLE_SUDO_GROUP_RULE
-	$(SED) '/^# \%sudo\tALL=(ALL) ALL/s/^# //' $(TARGET_DIR)/etc/sudoers
+	$(SED) '/^# \%sudo\tALL=(ALL:ALL) ALL/s/^# //' $(TARGET_DIR)/etc/sudoers
 endef
 SUDO_POST_INSTALL_TARGET_HOOKS += SUDO_ENABLE_SUDO_GROUP_RULE