grep: bump to version 2.13

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/grep/grep.mk

@@ -4,7 +4,7 @@
 #
 #############################################################
 
-GREP_VERSION = 2.12
+GREP_VERSION = 2.13
 GREP_SITE = $(BR2_GNU_MIRROR)/grep
 GREP_SOURCE = grep-$(GREP_VERSION).tar.xz
 GREP_CONF_OPT = --disable-perl-regexp --without-included-regex