pcre: bump version

Signed-off-by: Alexander Khryukin <alexander@mezon.ru>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/pcre/pcre.mk

@@ -4,7 +4,7 @@
 #
 #############################################################
 
-PCRE_VERSION = 8.30
+PCRE_VERSION = 8.31
 PCRE_SITE = ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre
 PCRE_LICENSE = BSD-3c
 PCRE_LICENSE_FILES = LICENCE