package/zeromq: disable -Werror

This will avoid the following build failure with openpgm 5.3:

In file included from /home/fabrice/buildroot/output/host/bin/../arm-buildroot-linux-gnueabihf/sysroot/usr/include/pgm-5.3/pgm/skbuff.h:39,
                 from /home/fabrice/buildroot/output/host/bin/../arm-buildroot-linux-gnueabihf/sysroot/usr/include/pgm-5.3/pgm/msgv.h:33,
                 from /home/fabrice/buildroot/output/host/bin/../arm-buildroot-linux-gnueabihf/sysroot/usr/include/pgm-5.3/pgm/pgm.h:44,
                 from src/ip.cpp:67:
/home/fabrice/buildroot/output/host/bin/../arm-buildroot-linux-gnueabihf/sysroot/usr/include/pgm-5.3/pgm/socket.h:207:1: error: ‘const char* pgm_family_string(int)’ defined but not used [-Werror=unused-function]
  207 | pgm_family_string (
      | ^~~~~~~~~~~~~~~~~

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/zeromq/zeromq.mk

@@ -8,7 +8,7 @@ ZEROMQ_VERSION = 4.3.2
 ZEROMQ_SITE = https://github.com/zeromq/libzmq/releases/download/v$(ZEROMQ_VERSION)
 ZEROMQ_INSTALL_STAGING = YES
 ZEROMQ_DEPENDENCIES = util-linux
-ZEROMQ_CONF_OPTS = --without-documentation
+ZEROMQ_CONF_OPTS = --disable-Werror --without-documentation
 ZEROMQ_LICENSE = LGPL-3.0+ with exceptions
 ZEROMQ_LICENSE_FILES = COPYING COPYING.LESSER
 # We're patching acinclude.m4