external/gpgmepp: silence -Werror=deprecated-copy (GCC trunk towards GCC 9)

Change-Id: Ib516eb3c9905577f083b99dd972443dcb3e86a42
Reviewed-on: https://gerrit.libreoffice.org/58043
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

external/gpgmepp/UnpackedTarball_gpgmepp.mk

@@ -25,5 +25,6 @@ $(eval $(call gb_UnpackedTarball_add_patches,gpgmepp, \
     external/gpgmepp/w32-build-fixes-2.patch \
     $(if $(filter LINUX,$(OS)),external/gpgmepp/asan.patch) \
     $(if $(filter LINUX,$(OS)),external/gpgmepp/rpath.patch) \
+    external/gpgmepp/gcc9.patch \
 ))
 # vim: set noet sw=4 ts=4:

external/gpgmepp/gcc9.patch

+--- lang/cpp/src/key.h
++++ lang/cpp/src/key.h
+@@ -62,6 +62,7 @@
+     /* implicit */ Key(const Null &);
+     Key(const shared_gpgme_key_t &key);
+     Key(gpgme_key_t key, bool acquireRef);
++    Key(Key const &) = default;
+ 
+     static const Null null;
+