[libgdamm] configure.ac: Use the same warnings as glibmm.

[Murray Cumming <murrayc src gnome org>]

commit a6b5fa27d3e7824ad07d81d5b00addd4309467e7
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Aug 22 12:24:50 2015 +0200

    configure.ac: Use the same warnings as glibmm.
    
    Adding -Wformat-security -Wsuggest-override -Wshadow .

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 451dd2d..c4890c4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -58,7 +58,7 @@ MM_PKG_CONFIG_SUBST([GMMPROC_DIR], [--variable=gmmprocdir glibmm-2.4])
 AC_LANG([C++])
 MM_ARG_ENABLE_WARNINGS([LIBGDAMM_WXXFLAGS],
                        [-Wall],
-                       [-pedantic -Wall -Wextra -Wno-long-long -Wno-missing-field-initializers 
-DGSEAL_ENABLE],
+                       [-pedantic -Wall -Wextra -Wformat-security -Wsuggest-override -Wshadow -Wno-long-long 
-Wno-missing-field-initializers -DGSEAL_ENABLE],
                        [G GDA GLIBMM])
 
 MM_ARG_ENABLE_DOCUMENTATION