cppzmq: upgrade 4.7.1 -> 4.8.0

Fixed:

Fix MSYS libzmq discovery (openembedded#510)
Fix handshake event don't need DRAFT API in libzmq v4.3.0 and above (openembedded#509)
Use chrono duration for poll default timeout (openembedded#497)
context_t close no longer uses deprecated function (openembedded#490)
Fix for potential memory leak in monitor_t::check_event (openembedded#482)
Fix if constexpr warnings on MSVC (openembedded#460)
Fix conversion warnings (openembedded#459)
Deprecate confusing connected() function (openembedded#458)
Added:

Add all draft socket types up to libzmq 4.3.4 (openembedded#488)
Add support for socket_ref to multipart_t ctor/send/recv (openembedded#487, openembedded#470)
Expose zmq::fd_t (openembedded#452)
Add poller_t::size function (openembedded#451)

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-connectivity/zeromq/cppzmq_git.bb

@@ -4,10 +4,10 @@ LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=db174eaf7b55a34a7c89551197f66e94"
 DEPENDS = "zeromq"
 
-SRCREV = "76bf169fd67b8e99c1b0e6490029d9cd5ef97666"
-PV = "4.7.1"
+SRCREV = "267d300d1c99381a0fbc7e060ae2899e51f5e425"
+PV = "4.8.0"
 
-SRC_URI = "git://github.com/zeromq/cppzmq.git;branch=bugfix-4-7-1"
+SRC_URI = "git://github.com/zeromq/cppzmq.git;branch=master"
 
 S = "${WORKDIR}/git"