build-sys: ignore -Waddress message so that build works on gcc/rawhide

Newer gccs warn if you compare an address of a variable that is allocated
on the stack or is static with NULL. Since we compile dbus with -Werror
this causes the build to fail since we do this check all the time due to
macros such as _DBUS_ASSERT_ERROR_IS_SET().

configure.in

@@ -1175,6 +1175,11 @@ if test "x$GCC" = "xyes"; then
   *) CFLAGS="$CFLAGS -Wcast-align" ;;
   esac
 
+  case " $CFLAGS " in
+  *[\ \	]-Wno-address[\ \	]*) ;;
+  *) CFLAGS="$CFLAGS -Wno-address" ;;
+  esac
+
   case " $CFLAGS " in
   *[\ \	]-Wfloat-equal[\ \	]*) ;;
   *) if cc_supports_flag -Wfloat-equal; then