Drop use-older-tools patch, not needed on Debian Stretch or newer

debian/patches/series

@@ -1,2 +0,0 @@
-
-use-older-tools

debian/patches/use-older-tools

@@ -1,41 +0,0 @@
-Use older versions of Automake and GNU Gettext
---- a/configure.ac
-+++ b/configure.ac
-@@ -35,7 +35,7 @@
- AC_CONFIG_SRCDIR([src/trader.c])
- AC_CONFIG_AUX_DIR([build-aux])
- AC_CONFIG_HEADERS([config.h])
--AM_INIT_AUTOMAKE([1.15 -Wall -Werror foreign dist-xz])
-+AM_INIT_AUTOMAKE([1.14 -Wall -Werror foreign dist-xz])
- AM_MAINTAINER_MODE([enable])
- AC_CONFIG_LIBOBJ_DIR([lib])
- 
-@@ -54,7 +54,7 @@
- AC_TYPE_SSIZE_T
- 
- AM_GNU_GETTEXT([external])
--AM_GNU_GETTEXT_VERSION([0.19.8])
-+AM_GNU_GETTEXT_VERSION([0.19.3])
- 
- gl_INIT
- 
---- a/INSTALL
-+++ b/INSTALL
-@@ -39,7 +39,7 @@
-     multibyte character sequences (such as UTF-8) require a wide-character
-     version of Curses, such as NcursesW, to work correctly.
- 
--4.  The GNU Gettext library, version 0.19.8 or later, to allow the game to
-+4.  The GNU Gettext library, version 0.19.3 or later, to allow the game to
-     use languages other than English;  this is also called Native Language
-     Support.  If you do not have  this library (and do not wish to install
-     it), you may pass "--disable-nls" to the configure script.
-@@ -169,7 +169,7 @@
- following additional tools installed on your system to do so:
- 
- 1.  Autoconf v2.69 or later (http://www.gnu.org/software/autoconf/)
--2.  Automake v1.15 or later (http://www.gnu.org/software/automake/)
-+2.  Automake v1.14 or later (http://www.gnu.org/software/automake/)
- 3.  GNU Portability Library (http://www.gnu.org/software/gnulib/)
- 
- The  GNU Portability Library  may  be installed  by retrieving  the latest