shadowsocks-libev: bump to version 3.1.1

Notable changes since 3.1.0

    26ae365: fix possible socks5 exchange corruption caused by bad
             state transition when parsing responses
    f19a96e: fix segfault when presented with config {"mode": null}

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

net/shadowsocks-libev/Makefile

@@ -13,12 +13,12 @@ include $(TOPDIR)/rules.mk
 # - check if default mode has changed from being tcp_only
 #
 PKG_NAME:=shadowsocks-libev
-PKG_VERSION:=3.1.0
+PKG_VERSION:=3.1.1
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://github.com/shadowsocks/shadowsocks-libev/releases/download/v$(PKG_VERSION)
-PKG_HASH:=3b6493ebdcfff1eb31faf34d164d57049f7253ff5bffafa6ce2263c9ac123f31
+PKG_HASH:=24a002c100fbe9b4481e3134273cb1a2f25a4026eb030760e7e7eb57f8466ef6
 
 PKG_MAINTAINER:=Yousong Zhou <yszhou4tech@gmail.com>