Upping the required version of Automake, to ensure the ONCE macros are defined.

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@4706 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

 2014-04-02  Benno Schulenberg  <bensberg@justemail.net>
 	* configure.ac, doc/Makefile.am: Try to build the info documentation
 	only when 'makeinfo' is available.  Patch partly by Mike Frysinger.
+	* configure.ac: Upping the required version of Automake, to ensure the
+	ONCE macros are defined.  Suggested by Kamil Dudka and Mike Frysinger.
 
 2014-04-02  Mike Frysinger  <vapier@gentoo.org>
 	* doc/man/{,fr}/Makefile.am: Simplify the man rules still further.

configure.ac

@@ -26,7 +26,9 @@ AC_CANONICAL_HOST
 AM_INIT_AUTOMAKE
 AC_CONFIG_HEADERS([config.h])
 
-AC_PREREQ(2.54)
+dnl Make sure the ONCE macros are available.
+
+AC_PREREQ(2.61)
 
 dnl Checks for programs.
 
@@ -415,12 +417,15 @@ fi
 dnl Checks for typedefs, structures, and compiler characteristics.
 
 dnl Checks for available flags.
+
 AX_CHECK_COMPILE_FLAG([-Wall], [CFLAGS="$CFLAGS -Wall"], [], [])
 
 dnl Checks for library functions.
+
 AC_TYPE_SIGNAL
 AC_FUNC_VPRINTF
 AC_CHECK_FUNCS(getopt_long)
+
 dnl Checks for libraries.
 
 if eval "test x$CURSES_LIB_NAME = x"; then