[gcab] build-sys: silence bad-function-cast

[Marc-Andre Lureau <malureau src gnome org>]

commit 4f4fa563d742ad510544213c67330667027b38c2
Author: Marc-André Lureau <marcandre lureau gmail com>
Date:   Fri Jul 31 00:28:01 2015 +0200

    build-sys: silence bad-function-cast
    
    Warns with valid code in enum registration

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 180a2ce..2b6f2b6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,6 +42,7 @@ nw="$nw -Wsign-conversion"      # Likewise.
 nw="$nw -Wunused-parameter"     # Likewise.
 nw="$nw -Wunused-local-typedefs" # Likewise.
 nw="$nw -Wunsafe-loop-optimizations" # Likewise.
+nw="$nw -Wbad-function-cast"    # Likewise.
 # Enable all GCC warnings not in this list.
 gl_MANYWARN_COMPLEMENT([warnings], [$warnings], [$nw])
 for w in $warnings; do