nng: upgrade 1.11 -> 1.12.3

These are bug fix releases, including fixes for a few security bugs.
Running ptest on nodistro qemux86-64 shows all tests passing, including
the previously failing 'httpclient' test.

Changelogs:
* https://github.com/nanomsg/nng/releases/tag/v1.12.3
* https://github.com/nanomsg/nng/releases/tag/v1.12.2
* https://github.com/nanomsg/nng/releases/tag/v1.12.1
* https://github.com/nanomsg/nng/releases/tag/v1.12.0

Signed-off-by: Nate Kent <nate@nkent.net>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-networking/recipes-connectivity/nanomsg/nng_1.12.3.bb

@@ -9,7 +9,7 @@ SRC_URI = "git://github.com/nanomsg/nng.git;branch=stable;protocol=https \
            file://run-ptest \
           "
 
-SRCREV = "84aa701f42968bf536141a24e826da66963b571a"
+SRCREV = "73f715235967afc783e0b99c52d015dc10897fda"
 
 inherit cmake pkgconfig ptest