gnupg21: Removes previously backported patch

fix-gpgsm-linking.patch was backported from gnupg master for 2.1.14. It
is included in 2.1.15, making the patch un applicable.

Fixes 447207d21d

pkgs/tools/security/gnupg/21.nix

@@ -27,10 +27,6 @@ stdenv.mkDerivation rec {
     readline libusb gnutls adns openldap zlib bzip2
   ];
 
-  # gpgsm-linking is fixed by commit (c49c43d7) in the gnupg master branch;
-  # fix-gpgsm-linking.patch should be dropped after gnupg 2.1.15 is released
-  patches = [ ./fix-gpgsm-linking.patch ];
-
   postPatch = stdenv.lib.optionalString stdenv.isLinux ''
     sed -i 's,"libpcsclite\.so[^"]*","${pcsclite}/lib/libpcsclite.so",g' scd/scdaemon.c
   ''; #" fix Emacs syntax highlighting :-(

pkgs/tools/security/gnupg/fix-gpgsm-linking.patch

@@ -1,11 +0,0 @@
---- a/tests/gpgscm/Makefile.in
-+++ b/tests/gpgscm/Makefile.in
-@@ -457,7 +457,7 @@
- 	scheme-config.h opdefines.h scheme.c scheme.h scheme-private.h
- 
- gpgscm_LDADD = $(LDADD) $(common_libs) \
--	$(NETLIBS) $(LIBICONV) $(LIBREADLINE) \
-+	$(NETLIBS) $(LIBICONV) $(LIBREADLINE) $(LIBINTL) \
- 	$(LIBGCRYPT_LIBS) $(GPG_ERROR_LIBS)
- 
- t_child_SOURCES = t-child.c