Don't do -Werror it breaks builds on some scenarios with trivialities.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

diff -Nura lxc-lxc-1.0.4/configure.ac lxc-lxc-1.0.4.orig/configure.ac
--- lxc-lxc-1.0.4.orig/configure.ac	2014-07-04 10:31:19.821029891 -0300
+++ lxc-lxc-1.0.4/configure.ac	2014-06-13 14:07:45.000000000 -0300
@@ -560,7 +560,7 @@
 LXC_CHECK_TLS
 
 if test "x$GCC" = "xyes"; then
-	CFLAGS="$CFLAGS -Wall -Werror"
+	CFLAGS="$CFLAGS -Wall"
 fi
 
 # Files requiring some variable expansion