shadowsocks-libev: convert to PCRE2
Convert package to PCRE2 by porting a pending patch from a closed PR.
The PR is old but the code never changed and is simple enough to check
the changes. The patch apply directly with no changes (aside from
commenting out the travis CI file)
The PR was never merged as PCRE2 at times was too new and they were
trying to find a better regex lib.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
(cherry picked from commit
db305165c9a0b9b69a83f6379d0994c3708d58e8)