contrib: bump pcre

8.36 is not hosted anymore. Bump to latest 8.38.

Tuleap: #124
Change-Id: Ib40e60979d2ac1909cf8810a45a7dc9a0bf013cc

contrib/src/pcre/SHA512SUMS

-acd2bc6911be7b518ad4aca3c3ccbe98bdbeabf0e77d6b04009838c7825b563a001377f8c3a6a8a0583ec32ee9fefe05e3c1a69f272fe5084469a6b6c2148fbf  pcre-8.36.tar.bz2
+ad3412ceee8f992787a3e7cbe0155ffba67affd4b2dfece6c4501dc8d2012f52dcc1ee1f56759362e04bbbd10ea9370b3e46f238e2f75005cb69f6c8439e52c0  pcre-8.38.tar.bz2

contrib/src/pcre/rules.mak

 # Perl Compatible Regular Expression
 
-PCRE_VERSION := 8.36
+PCRE_VERSION := 8.38
 PCRE_URL := ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-$(PCRE_VERSION).tar.bz2
 
 PKGS += pcre