Mdnssd: Disable gcc warnings about initialized but unused variables

We want to stay in sync with upstream, therefore just disable the
warnings.

Change-Id: Ia49e3e5581dfe8719b622524f2484d19952b5b7b
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@nokia.com>

src/tools/mdnssd/mdnssd.pro

@@ -46,6 +46,10 @@ HEADERS += \
     DebugServices.h \
     dns_sd.h
 
+*-g++ {
+    QMAKE_CFLAGS += -Wno-unused-but-set-variable
+    QMAKE_CXXFLAGS += -Wno-unused-but-set-variable
+}
 linux-* {
 DEFINES += NOT_HAVE_SA_LEN USES_NETLINK HAVE_LINUX TARGET_OS_LINUX
 }