[master] use the WARNING_NO_MISSING_FIELD_INITIALIZERS_CFLAG

Some versions of GCC warn about some versions of Boost regarding
missing initializer for members in its posix_time.
https://svn.boost.org/trac/boost/ticket/3477
But older GCC compilers don't have the flag.

This is the same as on a few other Makefiles too.

src/lib/dhcp/Makefile.am

@@ -5,6 +5,12 @@ AM_CPPFLAGS += $(BOOST_INCLUDES)
 
 AM_CXXFLAGS = $(B10_CXXFLAGS)
 
+# Some versions of GCC warn about some versions of Boost regarding
+# missing initializer for members in its posix_time.
+# https://svn.boost.org/trac/boost/ticket/3477
+# But older GCC compilers don't have the flag.
+AM_CXXFLAGS += $(WARNING_NO_MISSING_FIELD_INITIALIZERS_CFLAG)
+
 CLEANFILES = *.gcno *.gcda
 
 lib_LTLIBRARIES = libdhcp++.la

src/lib/dhcp/tests/Makefile.am

@@ -7,6 +7,12 @@ AM_CPPFLAGS += -DINSTALL_PROG=\"$(abs_top_srcdir)/install-sh\"
 
 AM_CXXFLAGS = $(B10_CXXFLAGS)
 
+# Some versions of GCC warn about some versions of Boost regarding
+# missing initializer for members in its posix_time.
+# https://svn.boost.org/trac/boost/ticket/3477
+# But older GCC compilers don't have the flag.
+AM_CXXFLAGS += $(WARNING_NO_MISSING_FIELD_INITIALIZERS_CFLAG)
+
 if USE_STATIC_LINK
 AM_LDFLAGS = -static
 endif

tests/tools/perfdhcp/Makefile.am

@@ -6,6 +6,12 @@ AM_CPPFLAGS += $(BOOST_INCLUDES)
 
 AM_CXXFLAGS = $(B10_CXXFLAGS)
 
+# Some versions of GCC warn about some versions of Boost regarding
+# missing initializer for members in its posix_time.
+# https://svn.boost.org/trac/boost/ticket/3477
+# But older GCC compilers don't have the flag.
+AM_CXXFLAGS += $(WARNING_NO_MISSING_FIELD_INITIALIZERS_CFLAG)
+
 AM_LDFLAGS = $(CLOCK_GETTIME_LDFLAGS)
 AM_LDFLAGS += -lm
 if USE_STATIC_LINK