configure: GNU_SOURCE is redundant

You only want either use_extensions or gnu_source. use_extensions is
the modern preferred way to enable gnu_source.

This commit fixes a lot of useless warnings at autoreconf time.

diff --git a/configure.ac b/configure.ac
index 039ab50..ab84b42 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,6 @@ AC_CONFIG_AUX_DIR([build-aux])
 
 dnl AM_INIT_AUTOMAKE([silent-rules])
 AC_USE_SYSTEM_EXTENSIONS
-AC_GNU_SOURCE
 AM_INIT_AUTOMAKE
 AM_PROG_CC_C_O
 AM_MAINTAINER_MODE()